Pipetting device, pipette tip coupler, and pipette tip: devices and methods

ABSTRACT

Pipette assembly that includes a pipette device, a pipette tip, and a leaf spring coupling device coupling the tip to the pipette device, the coupling device comprising a plurality of circumferentially disposed elements or segments in the form of flexible leaf springs with stabilizer plateaus used to retain a pipette tip to the coupler and prevent the pipette tip from rocking on the coupler and a distal elastomeric element, such as an O-ring, and the pipette tip comprising dual complemental working surfaces in the pipette tip to provide precise control of an axial coupled position defined as an axial distance from a distally facing axial stop surface of the pipette tip coupler to the end of the pipette tip that contacts liquid when the pipette tip coupler and disposable pipette tip are in a coupled configuration.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. section 119(e) and 120, this application is acontinuation-in-part of and claims the benefit of priority from U.S.patent application Ser. No. 16/514,567 entitled “Pipetting Device,Pipette Tip Coupler, and Pipette Tip: Devices and Methods” filed on Jul.17, 2019, U.S. Pat. No. 10,730,040 which is a continuation of and claimsthe benefit of priority from U.S. Pat. No. 10,525,460 entitled“Pipetting Device, Pipette Tip Coupler, and Pipette Tip: Devices andMethods” issued on Jan. 7, 2020, which claims the benefit of priorityfrom two (2) U.S. provisional patent applications, No. 62/350,291 filedon Jun. 15, 2016 and No. 62/350,302 filed on Jun. 15, 2016, all of whichare fully incorporated herein by reference.

FIELD

This disclosure pertains generally to pipetting devices, and moreparticularly to pipette tip couplers, disposable pipette tips, pipettetip and coupler combinations, and coupling and decoupling methods of atleast one disposable pipette tip to or from at least one pipette tipcoupler operatively carried by a pipette device.

BACKGROUND

Pipette devices are used in a multitude of industries for the transferof liquids to conduct experimental analysis. As such, to provide controlwithin the experiments being performed, disposable pipette tips are usedand intended for one-time use. Disposable pipette tips are employed withboth manual pipette devices and automated pipette devices having a largenumber of pipette units arranged in a row or in a matrix for aspiratingsamples simultaneously from a large number of vessels and dispensingthem elsewhere.

Disposable pipette tips have been constructed historically to interfaceto either a conical or stepped coupling stud. In the cases where aconical coupling stud is used, the disposable pipette tip is constructedin a manner that it must be pre-stressed onto the coupling stud toprovide an airtight seal. Due to the tolerances of the two interfacingcomponents, the distance to the end of the pipette tip that comes incontact with liquid is not well controlled. In addition, high pressforces are required to pre-stress the pipette tip to create the airtight seal. As a result, microfissures may be formed in the pipette tip,which are a cause of leakage. Moreover, the high press forces uponplacement of the pipette tip have the disadvantage that for the releaseof the pipette tip correspondingly high forces have to be applied.

The assignee of the present application, HAMILTON Company, teaches inU.S. Pat. No. 7,033,543, issued Apr. 25, 2006, a stepped coupling studin conjunction with an O-ring that provides a solution for reducing thehigh press force required to create an air tight seal as well asproviding well defined axial positioning of the end of the pipette tipthat comes in contact with liquid. As the O-ring is compressed, itprovides axially directed force to not only provide the air-tight seal,but to engage the axial coupling feature on the coupling stud to thecounter axial coupling feature on the pipette tip.

Notwithstanding, current systems utilizing a stepped coupling stud and asolitary O-ring configuration are problematic when the O-ring becomescompromised because the result is an impairment in the air-tight sealand the performance of the pipette device.

Additionally, the compression of the O-ring results in the deformationof the O-ring which in turn provides the axially directed force andair-tight seal against the working surface of the pipette tip. Counterto this operation, when the compression of the O-ring is removed, theO-ring must disengage from the working surface of the pipette tip toallow the pipette tip to be removed from the coupling stud and thepipette device for disposal. If the O-ring does not fully decompress,some residual force will remain resulting in keeping the pipette tipengaged to the coupling stud and thus requiring an automated externalaxial counterforce to remove the pipette tip for disposal.

Moreover, as the size of the holes to and/or from which liquid istransferred decreases, the need for precision positioning of all of thepipette tips in a controlled manner increases in order to allowsuccessful targeting.

Hence, there is a need to ameliorate or overcome one or more of thesignificant shortcomings delineated hereinabove.

SUMMARY

Accordingly, and in one aspect, an embodiment of the present disclosureameliorates or overcomes one or more of the shortcomings of the knownprior art by providing a pipette tip coupler and disposable pipette tipcombination which comprises a plurality of circumferentially disposedelements or segments engaging a circumferential interior working surfacedefining a first working surface formed into an interior circumscribingsurface of a sidewall of the pipette tip in an area superior to aproximally facing axial stop surface of the pipette tip for providing aresultant pre-stress force which pre-stresses the pipette tip axiallyupward causing a distal elastomeric element of the coupler to bepre-stressed against a second interior working surface of the pipettetip forming a seal configuration that eliminates the seal deteriorationor failure of the known prior art.

In addition, and in one aspect, the distal elastomeric element, whencompressed against the second interior working surface, provides acounter axial force to the plurality of elements or segments wherein atleast one benefit of this counter axial force is that additional forceis applied to the first working surface by the plurality of individualelements or segments when the plurality of individual elements orsegments are in a radially and axially interfacing state for providing astronger distal seal.

A further benefit of the counter axial force is that when the pluralityof individual elements or segments are disengaged to a radiallyretracted state, the counter axial force of the distal elastomericelement defines a counter axially directed disengaging force that aidsin the removal of the pipette tip from the pipette tip coupler fordisposal.

In another aspect, an embodiment of the present disclosure provides apipette tip coupler and disposable pipette tip combination, the couplercomprising a plurality of circumferentially disposed elements orsegments and a distal elastomeric element in the form of, but notlimited to, an O-ring and the pipette tip comprising dual complementalinterior working surfaces in the pipette tip to provide a resultantaxial force achieved from an engagement of the plurality of elements orsegments and the distal elastomeric element with the dual complementalworking surfaces for pre-stressing the disposable pipette tip into anaxial coupling position which is provided by a distally facing axialstop surface of the pipette tip coupler and a proximally facingcomplimentary counter axial stop surface of the disposable pipette tipsuch that a perpendicular datum is established to a longitudinal axis ofa channel of a pipette device carrying the pipette tip coupler anddisposable pipette tip combination which provides for pipette tipstraightness and controlled concentricity.

Thus, one benefit of the resultant axial force coupling position overthe known prior art is the establishment of this perpendicular datumwhich provides for pipette tip straightness and controlledconcentricity. Concentricity becomes worse as an angle defined herein as“ø” between a transverse axis and the longitudinal axis perpendicular tothe transverse axis is allowed to increase. Thus, controlledconcentricity becomes especially important on a multi-channel system andtargeting multiple wells. Accordingly, the pipette tip coupler anddisposable pipette tip combination provides tighter concentricity toallow for tighter precision of all the pipette tips in a controlledmanner allowing successful targeting of multiple wells and/or smallerholes to and/or from which liquid is transferred.

In another aspect, an embodiment of the present disclosure provides apipette tip coupler and disposable pipette tip combination, the couplercomprising a plurality of circumferentially disposed elements orsegments and a distal elastomeric element in the form of, but notlimited to, an O-ring and the pipette tip comprising dual complementalworking surfaces in the pipette tip to provide precise control of anaxial coupled position defined as an axial distance from a distallyfacing axial stop surface of the pipette tip coupler to the end of thepipette tip that contacts liquid when the pipette tip coupler anddisposable pipette tip are in a coupled configuration. This, combinedwith pipette tip straightness, allows for a pipette device carrying thepipette tip coupler and disposable pipette tip combination to targetsmaller holes. Additionally, smaller volumes of liquid can betransferred resulting from the known fixed distance of the disposablepipette tip allowing for a controlled touch of the pipette tip/liquid toa working surface onto or from which liquid is to be transferred.

In yet another aspect, an embodiment of the present disclosure providesa pipette tip coupler and disposable pipette tip combination comprisingan angled squeeze mechanism that directs the motion of the plurality ofindividual elements into contact with the first working surface of thepipette tip. The result is more axial force to pre-stress the pipettetip into the axial coupling position.

In yet another aspect, an embodiment of the present disclosure providesa pipette tip coupler and disposable pipette tip combination, thecoupler comprising a plurality of circumferentially disposed elements orsegments in the form of flexible leaf springs with retention bumps toretain a pipette tip to the coupler, stabilizer plateaus to prevent thepipette tip from rocking on the coupler and a distal elastomeric elementin the form of, but not limited to, an O-ring and the pipette tipcomprising dual complemental working surfaces in the pipette tip toprovide precise control of an axial coupled position defined as an axialdistance from a distally facing axial stop surface of the pipette tipcoupler to the end of the pipette tip that contacts liquid when thepipette tip coupler and disposable pipette tip are in a coupledconfiguration.

Further aspects of the embodiments of the present disclosure will becomeapparent from the detailed description provided below, when takentogether with the attached drawings and claims. It should be understood,however, that numerous modifications and adaptations may be resorted towithout departing from the scope and fair meaning of the claims as setforth below following the detailed description of preferred embodimentsof the present disclosure.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofthe disclosure, will be more fully understood by reference to thefollowing drawings which are for illustrative purposes only, and are notintended to limit the scope of the present disclosure. Also, it isappreciable that the drawings are not necessarily in scale as somecomponents may be shown to be enlarged or to be out of proportionrelative to the size in actual implementation in order to more clearlyillustrate one or more concepts of the present disclosure. In thedrawings:

FIG. 1 is a perspective view of an example embodiment of an airdisplacement pipette device assembly of an automated liquid handlingsystem.

FIG. 2 is a longitudinal sectional, side elevational view of the exampleembodiment of the pipette device assembly.

FIG. 3 is a fragmentary longitudinal sectional, side elevational view ofthe example embodiment of the pipette device assembly comprising apipette device operatively coupled to an example embodiment of anexpanding mandrel collet coupling device or pipette tip coupler that isoperatively coupled to an example embodiment of a disposable pipettetip.

FIG. 4 is a side elevational view of the example embodiment of thepipette device assembly.

FIG. 5 is a partial exploded parts perspective view of the pipettedevice assembly detailing parts of the example embodiment of theexpanding mandrel collet coupling device.

FIG. 6 is a fragmentary, partial exploded parts perspective viewdetailing parts of the example embodiment of the expanding mandrelcollet coupling device interposed between the disposable pipette tip andthe pipette device.

FIG. 7 is a side elevational view of the example embodiment of theexpanding mandrel collet coupling device.

FIG. 8 is a top and side perspective view of a central coupler body ofthe example embodiment of the expanding mandrel collet coupling device.

FIG. 9 is a top and side perspective view of an example embodiment of alower or distal elastomeric element or O-ring of the example embodimentof the expanding mandrel collet coupling device.

FIG. 10 is a top and side perspective view of the distal elastomericelement circumscribing a distal stem portion of the central coupler bodyand a cylindrical spacer circumscribing and mounted on the central bodyaxially above the distal elastomeric element.

FIG. 11 is a top and side perspective view of an example embodiment ofan expanding mandrel collet of the expanding mandrel collet couplingdevice.

FIG. 12 is a longitudinal sectional, side perspective view of theexample embodiment of the expanding mandrel collet of the expandingmandrel collet coupling device.

FIG. 13 is a top and side perspective view of an example embodiment ofan annular wedge of the example embodiment of the expanding mandrelcollet coupling device.

FIG. 14 is a side elevational view of the example embodiment of theexpanding mandrel collet in an expanded configuration by application ofa force from a piston sleeve or squeeze sleeve illustrated in fragment.

FIG. 15 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the expanding mandrel collet of theexpanding mandrel collet coupling device operatively coupled to thepipette device.

FIG. 16 is a fragmentary, partially sectional, side elevational view ofthe example embodiment of the disposable pipette tip operatively coupledto the pipette device by way of the embodiment of the expanding mandrelcollet coupling device.

FIG. 17 is a side elevational view of the example embodiment of thedisposable pipette tip illustrated in a supported position.

FIG. 18 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the disposable pipette tip detailing theinterior thereof.

FIG. 19 is a fragmentary, longitudinal sectional, side elevational viewof an upper coupling portion of the example embodiment of the disposablepipette tip detailing the upper coupling interior thereof.

FIG. 20 diagrammatical block diagram view of an example embodiment of anautomated pipetting workstation or system.

FIG. 21 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the pipette device supporting the exampleembodiment of the expanding mandrel collet coupling device over thedisposable pipette tip.

FIG. 22 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the expanding mandrel collet couplingdevice positioned over and into the disposable pipette tip defining acoupling stage with the distal elastomeric element initially contactinga sealing seat surface of the pipette tip and with the plurality ofdiscrete coupling elements or segments in an unsqueezed or radiallyoutwardly unextended state, the sealing seat surface having an acutesealing seat surface angle relative to the central longitudinal axis ofthe pipette tip.

FIG. 23 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the expanding mandrel collet couplingdevice and pipette tip with the pipette tip being lifted as a result ofthe piston sleeve pushing down on the annular wedge for radiallyextending a rounded part of a plurality of expanding mandrel colletsegments against an upper corner of a groove formed in the pipette tipresulting in an axial force that lifts or pulls the pipette tip up whichstarts the process of seating the pipette tip and compressing the distalelastomeric element against the sealing seat surface of the pipette tip.

FIG. 24 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the rounded surface of one of the plurality ofexpanding mandrel collet segment arms of the expanding mandrel collet ofthe segmented coupler being extended into contact with the corner of thegroove of the pipette tip as is illustrated in FIG. 23.

FIG. 25 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the distal elastomeric element in an initial compressedstate against the sealing seat surface of the pipette tip as isillustrated in FIG. 23.

FIG. 26 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the expanding mandrel collet couplingdevice positioned yet further into the pipette tip with the pipette tipbeing lifted while the piston sleeve further forces down on the annularwedge to continue radially extending the rounded surface of theplurality of expanding mandrel collet segments into the groove of thepipette tip further pulling the pipette tip up and further compressingthe distal elastomeric element against the sealing seat surface of thepipette tip.

FIG. 27 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the rounded surface of one of the plurality ofexpanding mandrel collet segments being further extended into the grooveof the pipette tip as is illustrated in FIG. 26.

FIG. 28 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the distal elastomeric element being further compressedfrom the initial compressed state against the sealing seat surface ofthe pipette tip as is illustrated in FIG. 26.

FIG. 29 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the expanding mandrel collet couplingdevice positioned in the disposable pipette tip with the pipette tipbeing lifted up to its final seated state by the annular wedge beingmoved to its final position thereby defining a final coupling state withthe distal elastomeric element in a final compressed seated sealingstate against the sealing seat surface of the pipette tip.

FIG. 30 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the rounded surface of one of the plurality ofexpanding mandrel collet segments being extended into abutment with thesurface defining the groove as is illustrated in FIG. 29.

FIG. 31 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the distal elastomeric element in the final compressedseated sealing state against the sealing seat surface of the pipette tipas is illustrated in FIG. 29.

FIG. 32 is a fragmentary, longitudinal sectional, side elevational,detailed view of onset of a coupling between the example embodiments ofthe expanding mandrel collet coupling device and disposable pipette tipwith an illustration of associated forces.

FIG. 33 is a fragmentary, longitudinal sectional, side elevational,detailed view of the onset of coupling of one of a plurality of arcuateor rounded segment surfaces of one of the plurality of expanding mandrelcollet segments with the groove of the example embodiment of thedisposable pipette tip with an illustration of associated forces.

FIG. 34 is a fragmentary, longitudinal sectional, side elevational,detailed view of the completed coupling state between the exampleembodiments of the expanding mandrel collet coupling device anddisposable pipette tip with an illustration of associated forces.

FIG. 35 is a fragmentary, longitudinal sectional, side elevational viewillustrating a misaligned coupling between example embodiments of anexpanding mandrel collet coupling device and disposable pipette tip fordefining misalignment parameters.

FIG. 36 is a fragmented and cutaway, longitudinal sectional, sideelevational view of an embodiment of a pipette device operativelycoupled to a misaligned coupling between example embodiments of anexpanding mandrel collet coupling device and disposable pipette tip fordefining misalignment parameters.

FIG. 37 is a fragmented and cutaway, longitudinal sectional, sideelevational view of the example embodiments of the air displacementpipette device coupled to the expanding mandrel collet coupling devicethat is coupled to the disposable pipette tip that has a small liquidvolume interposed between the end of the pipette tip and a workingsurface and the view further having dimensioning lines illustrated andidentified.

FIG. 38 is a fragmentary, longitudinal sectional, side elevational viewdetailing the interior of the example embodiment of the disposablepipette tip and the view further having dimensioning lines illustratedand identified.

FIG. 39 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the pipette device operatively coupled tothe example embodiment of the expanding mandrel collet coupling devicewith dimensioning lines relative to the dimensioning lines in FIG. 38illustrated and identified.

FIG. 40 is a longitudinal side elevational view of the pipette deviceassembly illustrating a circuit board that processes the signal from aLiquid Level Detection (LLD) circuit contact wherein the LLD circuitcontact is connected between the circuit board and squeeze sleeve thatis in contact with via an annular wedge the plurality of segments orelements coupling with the pipette tip wherein the distal end of thepipette tip is illustrated in contact with the liquid.

FIG. 41 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the expanding mandrel collet couplingdevice positioned over the example embodiment of the disposable pipettetip comprising an alternative sealing seat surface angle ofsubstantially ninety degrees relative to the central longitudinal axisof the pipette tip.

FIG. 42 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the expanding mandrel collet couplingdevice positioned in the disposable pipette tip comprising thealternative sealing seat surface angle of substantially ninety degreeswherein the pipette tip is lifted up to its final seated state and theannular wedge moved into its final position for defining a finalcoupling state with the distal elastomeric element in a final compressedand seated sealing state against the alternative sealing seat surfaceangle of substantially ninety degrees.

FIG. 43 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the distal elastomeric element in the final compressedstate against the alternative sealing seat surface angle ofsubstantially ninety degrees as is illustrated in FIG. 42.

FIG. 44 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the disposable pipette tip illustratingdetail of the upper interior of the disposable pipette tip comprisinganother alternative sealing seat surface in the form of acircumferential radially concave sealing seat surface.

FIG. 45 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the example embodiment of the disposable pipette tipillustrating detail of the circumferential radially concave sealing seatsurface illustrated in FIG. 44.

FIG. 46 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the disposable pipette tip illustratingdetail of a further alternative sealing seat surface in the form of acircumferential radially convex sealing seat surface.

FIG. 47 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the example embodiment of the disposable pipette tipillustrating detail of the circumferential radially convex sealing seatsurface illustrated in FIG. 46.

FIG. 48 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the disposable pipette tip illustrating ayet further alternative sealing seat surface in the form of acircumferential upward facing tooth edge sealing seat surface.

FIG. 49 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the example embodiment of the disposable pipette tipillustrating detail of the circumferential upward facing tooth edgesealing seat surface illustrated in FIG. 48.

FIG. 50 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the expanding mandrel collet couplingdevice positioned over the example embodiment of the disposable pipettetip comprising an alternative V-shaped groove defined by an V-shapedcircumferential interior surface of the disposable pipette tip openingtoward the longitudinal axis and having a V-shaped cross section asillustrated.

FIG. 51 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the expanding mandrel collet couplingdevice positioned in the disposable pipette tip comprising thealternative V-shaped groove wherein the pipette tip is lifted up to itsfinal state with the rounded surfaces of the plurality of expandingmandrel collet segments being extended into the V-shaped groove and intoabutment against the V-shaped circumferential interior surface with thedistal elastomeric element in a final compressed and seated sealingstate against the sealing seat surface of the pipette tip.

FIG. 52 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the rounded surface of one of the plurality ofexpanding mandrel collet segments being extended into the V-shapedgroove and abutting against the V-shaped circumferential interiorsurface defining the V-shaped groove as is illustrated in FIG. 51.

FIG. 53 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the expanding mandrel collet couplingdevice positioned over a second example embodiment of the disposablepipette tip.

FIG. 54 is a fragmentary, longitudinal sectional, side elevationaldetailed view detailing the interior of the second example embodiment ofthe disposable pipette tip.

FIG. 55 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the expanding mandrel collet couplingdevice positioned in the second example embodiment of the disposablepipette tip with a stop disk shoulder surface of the coupling deviceabutting against an axial stop surface of the second example embodimentof the disposable pipette tip and the rounded surfaces of the pluralityof expanding mandrel collet segments being extended against an interiorsurface of a circumscribing sidewall of the second example embodiment ofthe disposable pipette tip resulting in a deformation of the interiorsurface and with the distal elastomeric element in a final compressedand seated sealing state against the sealing seat surface of the secondexample embodiment of the disposable pipette tip.

FIG. 56 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the rounded surface of one of the plurality ofexpanding mandrel collet segments of the expanding mandrel colletcoupling device being extended against and deforming the interiorsurface of the circumscribing sidewall of the second example embodimentof the disposable pipette tip as is illustrated in FIG. 55.

FIGS. 57 through 67 are fragmentary, longitudinal sectional, sideelevational views of the example embodiment of the disposable pipettetip comprising alternative groove shape embodiments relative to thecircumferential annular tip groove illustrated in at least FIG. 19.

FIG. 68 is a top and side perspective view of a second or alternativeexample embodiment of an expanding mandrel collet of the expandingmandrel collet coupling device.

FIG. 69 is a longitudinal sectional, side perspective view of the secondor alternative example embodiment of the expanding mandrel collet of theexpanding mandrel collet coupling device.

FIG. 70 is a perspective view of an alternative example embodiment of anair displacement pipette device assembly of an automated liquid handlingsystem.

FIG. 71 is a longitudinal sectional, side elevational view of one sideof the alternative example embodiment of the pipette device assembly.

FIG. 72 is a fragmentary, longitudinal sectional, side elevational viewof another side of the alternative example embodiment of the pipettedevice assembly.

FIG. 73 is a partial exploded parts view of the pipette device assemblydetailing parts of the pipette device illustrated in FIG. 72.

FIG. 74 is a partial exploded parts perspective view of the pipettedevice assembly detailing parts of the example embodiment of a nozzleand a leaf spring coupling device.

FIG. 75 is a fragmentary, partial exploded parts perspective viewdetailing parts of the example embodiment of a nozzle and a leaf springcoupling device interposed between the disposable pipette tip and thepipette device.

FIG. 76 is a side elevational view of the example embodiment of a leafspring coupling device.

FIG. 77 is a top and side perspective view of the example embodiment ofthe leaf spring coupling device.

FIG. 78 is a top and side perspective view of an example embodiment of alower or distal elastomeric element or O-ring of the example embodimentof the leaf spring coupling device.

FIG. 79 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the nozzle and the leaf spring couplingdevice operatively coupled to the pipette device.

FIG. 80 is a fragmentary, partially sectional, side elevational view ofthe example embodiment of the disposable pipette tip operatively coupledto the pipette device by way of the embodiment of the nozzle and theleaf spring coupling device.

FIG. 81 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the pipette device supporting the exampleembodiment of the nozzle and the leaf spring coupling device over thedisposable pipette tip.

FIG. 82 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the nozzle and leaf spring coupling devicepositioned over and into the disposable pipette tip defining a couplingstage with the leaf springs compressed, with the retention bumpsbeginning to enter the groove of the pipette tip, and with the distalelastomeric element initially contacting a sealing seat surface of thepipette tip, the sealing seat surface having an acute sealing seatsurface angle relative to the central longitudinal axis of the pipettetip.

FIG. 83 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the rounded surface of one of the plurality ofretention bumps of one of the leaf springs of the leaf spring couplingdevice being in contact with the corner of the groove of the pipette tipas is illustrated in FIG. 82.

FIG. 84 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the distal elastomeric element in initial contact withthe sealing seat surface of the pipette tip as is illustrated in FIG.82.

FIG. 85 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the nozzle, the leaf spring coupling deviceand pipette tip with the retention bumps of the leaf springs snappedinto the groove of the pipette tip and the distal elastomeric elementcompressed and seated against the sealing seat surface of the pipettetip.

FIG. 86 is a fragmentary, longitudinal sectional, side elevational,detailed view of the onset of coupling of one of a plurality of arcuateor rounded segment surfaces of a retention bump of a leaf spring withthe groove of the example embodiment of the disposable pipette tip withan illustration of associated forces.

FIG. 87 is an fragmentary, longitudinal sectional, side elevational,detailed view of the onset of coupling of one of a plurality of arcuateor rounded segment surfaces of a retention bump of a leaf spring withthe groove of the example embodiment of the disposable pipette tip withan illustration of associated forces.

FIG. 88 is a fragmentary, longitudinal sectional, side elevational,detailed view of the completed coupling state between the exampleembodiments of the leaf spring coupling device and disposable pipettetip with an illustration of associated forces.

FIG. 89 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the pipette device operatively coupled tothe example embodiment of the leaf spring coupling device with Z axisshown.

FIG. 90 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the leaf spring coupling device positionedin the disposable pipette tip comprising the alternative sealing seatsurface angle of substantially ninety degrees wherein the pipette tip islifted up to its final seated state with the distal elastomeric elementin a final compressed and seated sealing state against the alternativesealing seat surface angle of ninety degrees.

FIG. 91 is a fragmentary, longitudinal sectional, side elevationaldetailed view of the distal elastomeric element in the final compressedstate against the alternative sealing seat surface angle of ninetydegrees as is illustrated in FIG. 90.

DETAILED DESCRIPTION

For the purpose of illustrating the disclosure, there are shown in thedrawings embodiments which are presently preferred. These exampleembodiments will now be described more fully with reference to theaccompanying drawings wherein like reference numerals are used to denotelike parts or portions throughout the description of the several viewsof the drawings.

Pipette Assembly with Expanding Mandrel Collet Coupling and Tip

FIGS. 1 and 2 illustrate an example embodiment of a pipette deviceassembly 10 comprising an example embodiment of a pipette device 20, anexample embodiment of an expanding mandrel collet coupling device 100 orpipette tip coupler, and an example embodiment of a disposable pipettetip 220 removably coupled to the pipette device 20 by way of theexpanding mandrel collet coupling device 100.

Pipette Device 20

Referring to FIG. 2, the pipette device 20 comprises a body 22supporting an aspirating and dispensing device 24 comprising a plunger26 operatively coupled to and driven by a motor 28. The plunger 26resides within a plunger cylinder 30 extending from a distal or lowerend 32 of the body 22 of the pipette device 20.

Pipette device 20 further comprises an aspirating and dispensingcylinder 34 that is at least partially disposed within plunger cylinder30 at a location axially aligned with and distally below the plunger 26.The aspirating and dispensing cylinder 34 distally transitions into adistal mounting flange 36 for attaching with the expanding mandrelcollet coupling device 100 which, in turn, removably couples with thedisposable pipette tip 220.

Referring to FIGS. 1, 3, and 15, the aspirating and dispensing cylinder34 further comprises an interior circumscribing sidewall 38 that definesan open ended pipette channel 40 extending therethrough. The open endedpipette channel 40 longitudinally extends along a longitudinal channelaxis 80 of the pipette device assembly 10 between an open upper endportion 42 and open lower end portion 44 of the aspirating anddispensing cylinder 34 for providing open communication between plunger26 and an exterior area adjacent distal mounting flange 36 wherein thedistal mounting flange 36 is operatively connected to a central bodymember 102 of the expanding mandrel collet coupling device 100 and thecentral body member 102 comprising an open ended central channel 136extending through the central body member 102 to provide opencommunication between the tip 220 and the aspirating and dispensingcylinder 34 via the expanding mandrel collet coupling device 100.

Piston or Squeeze Sleeve 46

Referring to FIGS. 3 and 4, the pipette device 20 further comprises ahollow piston or squeeze sleeve 46 having a proximal or upper end 48 anda distal or lower end 50. The squeeze sleeve 46 circumscribes both theplunger cylinder 30 and the aspirating and dispensing cylinder 34 and isoperatively coupled to a squeeze motor 52.

As illustrated in FIG. 4, the squeeze motor 52 of pipette deviceassembly 10 is supported on the body 22 of the device 20 and isoperatively coupled to and drives a lead screw 54 which, in turn,couples to an axially translating lead nut 56 that is operativelycoupled to a squeeze linkage 58. The squeeze linkage 58 is operativelycoupled to the proximal or upper end 48 of the squeeze sleeve 46 viasqueeze linkage arm 60 such that rotation of the squeeze motor 52 in afirst direction results in linear axial translation of the squeezesleeve 46 in a distal or vertically downward direction alonglongitudinal channel axis 80 (FIG. 3) and such that subsequent rotationof the squeeze motor 52 in a second or opposite direction results inlinear counter axial translation of the squeeze sleeve 46 in a proximalor vertically upward direction opposite the downward direction alonglongitudinal channel axis 80 (FIG. 3).

Ejection Sleeve 62

Referring to FIG. 4, the pipette device 20 further comprises an ejectionsleeve 62 used to eject the disposable pipette tip 220 from the pipettedevice 20 wherein the ejection sleeve 62 is axially movable relative tothe aspirating and dispensing cylinder 34 (FIG. 2) and comprises aproximal or upper end 64, a distal or lower end 66, and an ejectionsleeve arm 68 attached at a first end to the ejection sleeve 62 adjacentupper end 64 and having an opposing second end attached to a first endof a plunger device 70.

As illustrated in FIG. 5, the plunger device 70 comprises an opposingend surface 72 abutting one end of an ejection sleeve spring 74 havingan opposing spring end abutting against an upper surface portion 76 ofthe body 22 of device 20 wherein the ejection sleeve spring 74 iscaptured between the surfaces 72, 76 to be spring loaded to bias theplunger device 70 and attached sleeve 62 in a normally pipette tipejected state.

The normally pipette tip ejected state is configured to require a force,such as coupling to pipette tip 220, to overcome the ejection sleevespring force in order to axially push the ejection sleeve 62 to aretracted state as illustrated in FIG. 2. FIG. 2 further illustratesthat the spring 74 circumscribes a central spring guide member 78 forretaining the shape of the spring 74 and for preclude the spring 74 frombuckling.

Furthermore, the spring 74 is dimensioned in such a way that the forceexerted on the pipette tip 220 by sleeve 62 in the course of itsrelaxation is sufficient to assist in ejecting the tip 220 from theexpanding mandrel collet coupling device 100.

It should be appreciated that the expanding mandrel collet couplingdevice 100 and the disposable pipette tip 220 can be practiced on otherembodiments of pipette devices wherein the embodiment of pipette device20 is provided by way of example only and not limitation.

Expanding Mandrel Collet Coupling Device 100

Referring to FIGS. 5 through 7, the expanding mandrel collet couplingdevice 100 comprises an elongated central body member 102; a distal orlower elastomeric element 140 carried at a distal or lower end portionof the elongated central body member 102; an expanding collet 170configured to circumscribe the elongated central body member 102 andcomprising a segmented collar 200; and an annular wedge or washer 210.

The annular wedge 210 is configured to receive an upper portion of theelongated central body member 102 therethrough for axially movablysurmounting an interior of the expanding collet 170 adjacent segmentedcollar 200 for radially outwardly expanding the segmented collar 200from the unexpanded state having a first circumference to an expandedstate having a second conference greater than the first circumference asa function of the axial location of the annular wedge 210 relative tothe central body member 102 for engaging the interior of the pipette tip220 as illustrated in FIG. 29 from a disengaged state as illustrated inFIG. 21.

Elongated Central Body Member 102

More specifically, and referring to FIGS. 7 and 8, the expanding mandrelcollet coupling device 100 comprises the elongated central body member102 extending between a proximal or upper annular end face 104 and adistal or lower annular end face 130 along a longitudinal central axis90.

As illustrated in FIG. 8, the upper annular end face 104 of central bodymember 102 comprises an outer chamfered periphery 106 that transitionsinto an elongated tubular upper shank member 108 that distallytransitions into an annular tapered portion 110. In one embodiment,shank member 108 is threaded for assembly with distal mounting flange36, which has corresponding threads. Annular tapered portion 110decreases in diameter from shank member 108 and distally transitionsinto a cylindrical neck portion 112. The cylindrical neck portion 112distally transitions into a cylindrical collar 114 that has a diametergreater than a diameter of the cylindrical neck portion 112.

The cylindrical collar 114 is followed by a lower cylindrical bodymember 120 that has a diameter greater than a diameter of thecylindrical neck portion 112. Body member 120 distally extends from thecylindrical collar 114 to an upper annular shoulder end or stop surface122 of a distal cylindrical stem portion surface 124 that has a diametergreater than a diameter of the lower cylindrical body member 120.

As also illustrated in FIG. 8, the distal cylindrical stem portionsurface 124 transitions from upper annular shoulder end 122 into a roundend plate 126 having an upper surface 128 and a lower surface defined bythe distal or lower annular end face 130. As illustrated, the end plate126 has a diameter greater than a diameter of the stem portion surface124 wherein the distal stem portion surface 124 defines a distal orlower groove portion 132 of the expanding mandrel collet coupling device100.

Referring to FIGS. 8 and 15, the elongated central body member 102comprises an interior cylindrical channel surface 134 defining an openended cylindrically shaped central channel or passageway 136 extendingthrough the central body member 102 between the upper annular end face104 and the lower annular end face 130 along the longitudinal centralaxis 90 for providing open channel communication through the elongatedcentral body member 102 and to the open ended pipette channel 40longitudinally extending along the longitudinal channel axis 80 of thepipette device assembly 10.

Distal Elastomeric Element 140

As further illustrated in FIG. 7, the expanding mandrel collet couplingdevice 100 further comprises the distal or lower elastomeric element 140coaxially carried at the distal end portion of the elongated centralbody member 102.

In one embodiment, and referring FIG. 9, the distal elastomeric element140 comprises an annular body 142. Annular body 142 comprises aninterior surface 144 defining a central opening 146, a top surface 148,a peripheral exterior surface 150, and a bottom surface 152. Centralopening 146 is dimensioned to closely or tightly circumscribe the distalcylindrical stem portion 124 of the expanding mandrel collet couplingdevice 100 while shaped to reside within groove 132 and extend radiallyoutwardly circumferentially beyond end plate 126 as illustrated in FIG.7. In a relaxed or unsqueezed state, the distal elastomeric element 140comprises a circumferentially continuous, generally circular crosssection area 154 as is illustrated in FIG. 15.

Spacer 160

Referring to FIG. 10, the expanding mandrel collet coupling device 100further comprises a spacer 160 configured to circumscribe or beintegrally formed with the elongated central body member 102. Asillustrated, spacer 160 comprises a cylindrical body 162 extendingbetween a superior end 164 and an inferior end 165. The cylindrical body162 comprises an interior circumscribing surface 166 (FIG. 15) thatdefines an open ended passageway 168 extending through the body 162wherein the passageway 168 is dimensioned to closely or tightlycircumscribe the lower cylindrical body member 120 of the elongatedcentral body member 102.

Referring to FIGS. 7, 10, and 15, the spacer 160 is further configuredto be circumscribed by the expanding mandrel collet 170 wherein thesuperior end 164 of spacer 160 abuts against the distal end of themounting flange 36 and the inferior end 165 abuts against an interiorannular shoulder stop surface 177 of a annular base portion 172 of theexpanding mandrel collet 170 wherein the annular base portion 172further comprise a distal or lower annular end 176 that mounts on thedistal annular shoulder stop surface 122 of the distal cylindrical stemportion 124 (FIG. 8) of the elongated central body member 102 forsecuring the expanding mandrel collet 170 coaxially with the centralbody member 102 along the longitudinal central axis 90.

Referring to FIGS. 15 and 16, and as noted above, the shank member 108of the expanding mandrel collet coupling device 100 is configured to fitwithin the distal mounting flange 36 of the aspirating and dispensingcylinder 34 for operatively coupling the expanding mandrel colletcoupling device 100 to the pipette device 20 and removably coupling thedisposable pipette tip 220 to the pipette device 20 by way of theexpanding mandrel collet coupling device 100 such that the longitudinalchannel axis 80 and central axis 90 form a coincident or commonlongitudinal channel axis.

Expanding Mandrel Collet 170

Referring to FIGS. 7 and 11, the expanding mandrel collet 170 comprisesa plurality of circumferentially spaced apart upwardly extending colletarms 180 transitioning upwardly from ends 184 attached to the lowerannular base portion 172 to free segmented ends 200 defining thesegmented collar disposed axially above the lower annular base portion172. The plurality of circumferentially spaced apart upwardly extendingcollet arms 180 are separated from one another by one of a plurality ofcircumferentially spaced apart upwardly extending slots 182.

As illustrated in FIGS. 11 and 12, each of the plurality of upwardlyextending collet arms 180 comprises a respective lower arm portion 186transitioning into a respective upper arm portion 190. In oneembodiment, the plurality of circumferentially spaced apart lower armportions 186 form a generally cylindrically shaped circumscribing lowerbody portion 181 and the plurality of circumferentially spaced apartupper arm portions 190 form a frustoconically shaped circumscribingupper body portion 183 radially outwardly and upwardly transitioningfrom the lower body portion 181. The lower body portion 181 can beconfigured with a slight upward taper or increased circumference withrespect the distal or lower annular base portion 172.

Base Portion 172

Referring to FIGS. 11 and 12, the distal or lower annular base portion172 comprises a distally or downwardly facing base surface 171 and aproximally or upwardly facing base surface 173. The distally facing basesurface 171 downwardly transitions into an abbreviated distal or lowerend annular stem surface 174 that terminates to a distal or lowerannular base portion end 176 of the lower annular base portion 172. Thebase surface 171 and base portion 172 define an abbreviated distal endannular groove 178 as illustrated in FIG. 14.

Referring to FIGS. 12 and 15, the lower annular base portion 172 furthercomprises an inner cylindrical surface 175 upwardly transitioning intothe interior annular shoulder stop surface 177 on which spacer 160 ismounted on as illustrated in FIG. 15. Additionally, the innercylindrical surface 175 is dimensioned with an inner diameter thatclosely circumscribes lower cylindrical body member 120 of central bodymember 102 at a location directly above the annular shoulder stopsurface 122 of central body member 102 wherein the annular shoulder stopsurface 122 defines the axial stop for the lower annular base portionend 176 of the expanding mandrel collet 170 such that the expandingmandrel collet 170 is centrally mounted on and about the elongatedcentral body member 102.

Lower Arm Portions 186

As illustrated in FIG. 11, the lower arm portions 186 comprise distal orlower end portions 184 circumferentially spaced apart and attached tothe lower annular base portion 172. As illustrated in FIG. 12, the lowerarm portions 186 further comprise upper end portions defining medial armportions having interior annular recessed segmented surfaces or grooves191 and exterior radially outwardly extending annularly segmented stopdisk portions 194.

Referring to FIGS. 11 and 12, the segmented stop disks 194 circumscribeand radially extend from an exterior of the medial arm portions of theplurality of circumferentially spaced apart upwardly extending colletarms 180 defining an annular segmented stop disk.

As illustrated in FIG. 12, each of the segmented stop disks 194comprises a proximally or upwardly facing stop disk surface 198 and adistally or downwardly facing stop disk surfaces 196. Additionally, theplurality of lower arm portions 186 comprise inner cylindrical orinterior segmented surfaces 188 dimensioned with an inner diameter thatclosely circumscribes the spacer 160 which circumscribes the elongatedcentral body member 102.

The distal or lower end of the interior segmented surfaces 188 radiallyinwardly transition into the interior annular shoulder stop surface 177that provide the stop surface for spacer 160 as detailed above. Theproximal or upper end of the interior segmented surfaces 188 transitioninto the interior annular recessed segmented surface or groove 191.

Upper Arm Portions 190

Referring to FIGS. 11 and 12, the plurality of circumferentially spacedapart upper arm portions 190 upwardly and radially outwardly transitionfrom the respective lower arm portions 186 and terminate into aplurality of free ends 199 disposed above and radially outwardly fromthe lower arm portions 186 wherein the plurality of free ends 199comprise radially outwardly projecting segments defining segmentedcollar 200 wherein each segment comprises an exterior outwardly facingsurface 202 which, in in one embodiment is outwardly rounded or arcuatein shape corresponding to the arcuate groove of the example embodimentof the pipette tip.

Accordingly, the upper arm portions 190 upwardly and radially outwardlytransition from the segmented stop disks 194 to a plurality of radiallyoutwardly projecting segments defining segmented collar 200 wherein thesegmented collar 200 is configured to circumscribe longitudinal centralaxis 90 of the expanding mandrel collet coupling device 100 asillustrated in FIG. 7.

Additionally, the plurality of circumferentially spaced apart radiallyoutwardly and upwardly extending upper arm portions 190 including thesegments respectively comprise interior surfaces 192 forming an inclinedsegmented interior surface complemental to the proximally inclinedannular side surface 216 of the annular wedge 210 (FIG. 7) wherein eachcomprises a distally decreasing circumference relative to the Z axis andwherein the interior surfaces 192 of the upper arm portions 190 form aradially outwardly and upwardly extending conically shaped gap 204 withrespect to the elongated central body member 102 (FIG. 15).

In particularly, and as illustrated in FIG. 15, the upwardly andradially outwardly inclined inner surfaces 192 of the plurality ofcircumferentially spaced apart upper arm portions 190 define a distallytapering cone gap 204 between the inner surfaces 192 of the upper armportions 190 and the combination of the lower portion of the mountingflange 36 and the upper portion of spacer 160. The tapering cone gap 204is configured to receive the lower portion of annular wedge 210 suchthat the annular wedge shaped or inclined exterior side surface 216 ofthe annular wedge 210 abuts the inner surfaces 192 of the plurality offree ends 199 supporting the projecting segments defining segmentedcollar 200.

Annular Wedge 210

Referring to FIGS. 7, 13, and 15, the annular wedge 210 comprises aresilient wedge shaped annular body having a circumferentiallycontinuous, generally wedge shaped cross section 211. The annular wedge210 comprises a central interior annular surface 212 defining a centralannular opening 213 extending through the annular wedge 210 configuredto moveably circumscribe body 102.

Additionally, the annular wedge 210 comprises a top planar circularsurface 214 configured to make an electrical contact switch with the LLDcircuit ring end 366 of the LLD circuit 364 and radially outwardlyextending from the central interior annular surface 212 to acircumscribing outer edge surface 215.

Furthermore, the annular wedge 210 comprises a radially outwardlyproximally inclined side surface 216 radially upwardly and outwardlyextending from a bottom annular end 218 to an underside of an annularperipheral lip 219 that radially extends outwardly and terminates to thecircumscribing outer edge surface 215. Accordingly, radially outwardlyproximally inclined side surface 216 defines a distally tapering wedgesurface 216.

As illustrated in FIG. 15, the central annular opening 213 of theannular wedge 210 is dimensioned to allow passage of the distal mountingflange 36 and elongated tubular upper shank member 108 so as to allow aseating abutment of the radially outwardly proximally inclined sidesurface 216 of the annular wedge 210 with the inner surfaces 192 of theplurality of radially outwardly projecting segments 200 such that distalaxial translation of annular wedge 210 results in the radial projectionof the radially outwardly projecting segments 200 of the expandingmandrel collet 170 and subsequent proximal translation of annular wedge210 results in the radial retraction of the radially outwardlyprojecting segments 200 of the expanding mandrel collet 170.

As further illustrated in FIG. 15, the shank member 108 of the expandingmandrel collet coupling device 100 is configured to fit within thedistal mounting flange 36 of the aspirating and dispensing cylinder 34for operatively coupling the expanding mandrel collet coupling device100 to the pipette device 20 of the pipette device assembly 10 such thatthe longitudinal channel axis 80 and longitudinal central axis 90 form acoincident or common axis.

The expanding collet 170 is further configured to radially outwardlyexpand the segmented collar 200 from an unexpanded state having a firstcircumference as generally illustrated in FIG. 7 to an expanded statehaving a second circumference greater than the first circumference asgenerally illustrated in FIG. 14 when, under a force provided by thesqueeze sleeve 46, the annular wedge 210 moves axially downwardly.

Actuation of Squeeze Motor

Referring to FIG. 15, the expanding mandrel collet coupling device 100is configured to be fitted within the distal mounting flange 36 with thetop planar circular surface 214 of the annular wedge 210 disposedadjacent the distal end 50 of the squeeze sleeve 46. Accordingly, andreferring to FIGS. 4 and 15, the actuation of the squeeze motor 52 inthe first direction results in linear axial translation of the squeezesleeve 46 in a distal or vertically downward direction for applying aforce axially on top surface 214 of the annular wedge 210 resulting inthe distally tapering wedge surface 216 axially sliding down furtherinto the cone gap 204 for forcing the distally tapering wedge surface216 against the interior surfaces 192 of the plurality of radiallyoutwardly projecting segments 200 for pushing the exterior radiallyoutwardly facing surfaces 202 (FIG. 11) of the segments 200 radiallyoutwardly against the spring tension of upwardly extending collet arms180 and into contact with a first working surface of a pipette tip inthe form of a surface 244 defining a groove 246 of the disposablepipette tip 220 as exemplified in FIG. 29 described below.

Subsequent actuation of the squeeze motor 52 in the second direction,opposite the first direction, returns the distal end 50 of the squeezesleeve 46 to a home position illustrated in FIG. 15 such that theannular wedge member 210 axially slides up as a result the release ofthe stored potential energy in the upwardly extending collet arms 180thereby resulting in the retraction of the exterior radially outwardlyfacing surfaces 202 of the plurality of radially outwardly projectingsegments 200 from the groove 246 of the disposable pipette tip 220.

Pipette Tip 220

As illustrated in FIGS. 2 and 16, and as noted above, the expandingmandrel collet coupling device 100 provides an open communicationcoupling between the disposable pipette tip 220 and the pipette device20 of the pipette device assembly 10.

Referring to FIGS. 16 through 18, and in one example embodiment, thedisposable pipette tip 220 comprises an elongated tubular pipette tipbody 222 having a central longitudinal axis 224. Pipette tip body 222comprises an elongated circumscribing sidewall 226 longitudinallyextending along the central longitudinal axis 224 between a proximal orupper annular end face 228 and a distal or lower annular end face 230defining circumscribing open proximal and distal annular ends 232 and234 respectively. The elongated circumscribing sidewall 226 comprises aninterior surface 236 defining a pipette tip passage opening 238extending longitudinally along the central longitudinal axis 224 of thepipette tip body 222 between the open upper annular end 232 and the openlower annular end 234.

Accordingly, the pipette tip passage opening 238 provides opencommunication from an area exterior to the open distal annular end 234(FIG. 18), through the pipette tip 220, and to the pipette devicechannel 40 (FIG. 15) by way of the central channel 136 of the expandingmandrel collet coupling device 100 (FIG. 16) when the coupling device100 is coupled between the pipette device 20 and the pipette tip 220. Inthis coupling configuration, the central longitudinal axis 224 of thepipette tip body 222 is coextensive with the longitudinal channel axis80 of the pipette device 20.

In an alternate embodiment, the pipette tip passage opening 238 providesopen communication from an area exterior to the open distal annular end234 (FIG. 18), through the pipette tip 220, and to the pipette devicechannel 3040 (FIG. 79) by way of the central channel 3136 of nozzle 3102and the leaf spring coupling device 3100 (FIG. 80) when the nozzle 3102and the leaf spring coupling device 3100 are coupled between the pipettedevice 3020 and the pipette tip 220. In this coupling configuration, thecentral longitudinal axis 224 (FIG. 17) of the pipette tip body 222 iscoextensive with the longitudinal channel axis 3080 of the pipettedevice 3020.

First Interior Surface Section

Referring to FIG. 18, and in one example embodiment, the interiorsurface 236 of the elongated circumscribing sidewall 226 comprises anuppermost annular chamfered interior surface 240 that distally extendsradially inward from the proximal annular end face 228 of the pipettetip 220 and terminates by transitioning into a first substantiallycylindrical interior surface section 242 having a first diameter.

Axially Arcuate Circumferential Surface Defining a Groove

As illustrated in FIG. 18, and in one example embodiment, the firstsubstantially cylindrical interior surface section 242 comprises anaxially arcuate circumferential interior surface 244 formed into theelongated circumscribing sidewall 226 defining a circumferential annulargroove 246. Annular groove 246 divides the first substantiallycylindrical interior surface section 242 into an upper firstsubstantially cylindrical interior surface portion and a lower firstsubstantially cylindrical interior surface portion of substantiallyequal diameter. Accordingly, the annular groove 246 provides acircumferential radially outwardly extending concave shaped interiorsurface interruption of the first substantially cylindrical interiorsurface section 242 with an arcuate surface longitudinal cross section.The arcuate circumferential interior surface 244 is also configured inalternative surface cross sections as discussed below. And in oneembodiment, the first substantially cylindrical interior surface section242 is devoid of arcuate circumferential interior surface 244 definingthe circumferential annular groove 246.

Referring to FIGS. 18 and 19, the axially arcuate circumferentialinterior surface 244 defining the annular groove 246 comprises an upperannular transition edge 248 distally transitioning into an upper axiallyarcuate circumferential surface sector portion 250 of the axiallyarcuate circumferential interior surface 244. In succession, the upperaxially arcuate circumferential surface sector portion 250 distallytransitions into a lower axially arcuate circumferential surface sectorportion 252 of the axially arcuate circumferential surface 244. Then,lower axially arcuate circumferential surface sector portion 252terminates to a lower annular transition edge 254.

The upper axially arcuate circumferential surface sector portion orupper portion 250 provides the annular groove 246 with an increasingradius relative to the central longitudinal axis 224 (FIG. 17) of thepipette tip 220 from the upper annular transition edge 248 to a maximumradius of the annular groove 246 relative to the central longitudinalaxis 224 that defines a circumferential annular center of the annulargroove 246. The lower axially arcuate circumferential surface sectorportion or lower portion 252 provides the annular groove 246 with adecreasing radius relative to the central longitudinal axis 224 of thepipette tip 220 from the maximum radius defining the circumferentialannular center of the of the annular groove 246 to the lower annulartransition edge 254.

Second Interior Surface Section and Annular Shoulder Stop Surface

As illustrated in FIG. 18, the first substantially cylindrical interiorsurface section 242 is axially distally proceeded by a secondsubstantially cylindrical interior surface section 262 having a seconddiameter less than the first diameter of the first substantiallycylindrical interior surface section 242 for forming a proximallyfacing, radially inwardly extending annular shoulder seat surface oraxial stop surface 260 interposed between the first and secondsubstantially cylindrical interior surface sections 242, 262.

In one example embodiment, the proximally facing axial stop surface 260is substantially planar and generally perpendicular to the centrallongitudinal axis 224 of the pipette tip body 222 as illustrated in FIG.17.

Third Interior Surface Section and Sealing Seat

As also illustrated in FIGS. 18 and 19, the second substantiallycylindrical interior surface section 262 is axially distally proceededby a third substantially cylindrical interior surface section 272 havinga third diameter less than the second diameter of section 262.

Interposed between the second section 262 and the third section 272 is afrustoconical annular sealing seat or stop surface 270 defining acircumferential radially inwardly angled and distally extending distalworking surface 270. The frustoconical annular sealing seat surface 270comprises an upper annular sealing seat edge 266 defining an annularborder between the second substantially cylindrical interior surfacesection 262 and the frustoconical annular sealing seat surface 270. Inaddition, the frustoconical annular sealing seat surface 270 comprises alower annular sealing seat edge 268 defining an annular border betweenthe frustoconical annular sealing seat surface 270 and the thirdinterior surface section 272 wherein a diameter of the upper annularsealing seat edge 266 is greater than a diameter of the lower annularsealing seat edge 268.

Accordingly, the frustoconical annular sealing seat surface 270 definesthe circumferential radially inwardly angled and distally extendingsecond working surface or sealing seat surface 270 interposed betweenthe second substantially cylindrical interior surface section 262 andthe third substantially cylindrical interior surface section 272.

As illustrated, the sealing seat surface 270 is disposed at an acuteangle relative to the central longitudinal axis 224 wherein the acuteangle defines an acute sealing seat surface angle relative to thecentral longitudinal axis 224 (FIG. 17). In one embodiment, thepreferred acute sealing seat surface angle relative to the centrallongitudinal axis 224 is about 15 degrees to about 35 degrees with apreferred angle of about twenty-five degrees. As illustrated in FIG. 41,the acute sealing seat surface angle of an alternative sealing seatsurface 2270 relative to the central longitudinal axis 224 is about 90degrees.

Lower Interior Surface Portion

FIG. 18 further illustrates that in succession to the thirdsubstantially cylindrical interior surface section 272 is a fourthinterior surface section 274 that is distally followed by a fifthinterior surface section 275.

In one example embodiment, the fourth interior surface section 274distally tapers or decreases in diameter from a distal annular end 276of the third substantially cylindrical interior surface section 272 to aproximal annular end 278 of the fifth interior surface section 275. Inturn, the fifth interior surface section 275 distally tapers ordecreases in diameter from the proximal annular end 278 of the fifthinterior surface section 275 to the open distal annular end 234 of thepipette tip 220 that is intended for immersion. Additionally, and in oneexample embodiment, the fifth interior surface section 275 has a greatertaper than the fourth interior surface section 274.

External Longitudinal Ribs

Referring to FIG. 17, one example embodiment of the pipette tip 220comprises a plurality of circumferential spaced apart longitudinallyextending external ribs 280 disposed on the tubular pipette tip body 222adjacent the periphery of the proximal annular end face 228 andlongitudinally extending externally therefrom to an exterior area of thecircumscribing sidewall 226 that is adjacent to the third substantiallycylindrical interior surface section 272 as illustrated in FIG. 18.

In one example embodiment, the plurality of circumferential spaced apartlongitudinally extending external ribs 280 may be utilized to providesupport for the pipette tip 220 on or in a support surface 282 throughwhich the pipette body 222 has passed via, for example, a supportsurface aperture opening 284. One example embodiment of the supportsurface 282 can be in the form of, but not limited to, lab ware in theform of a tip rack as is known in the art, and informed by the presentdisclosure.

Automated Pipetting Workstation or System

Referring to FIGS. 5 and 20, and in one example of use and operation,one or more of the pipette device assemblies 10 is employed in anautomated pipetting workstation or system 300 that generally provides,but is not limited to, programmed transfers of liquid between containerswhich comprises mounting and ejection processes of one or moredisposable pipette tips 220 to the expanding mandrel collet couplingdevice 100 operatively carried by the pipette device 20 for carryingout, for example, the programmed transfers of liquid between containers.

In one example embodiment, the automated pipetting workstation 300generally comprises a robotic gantry 302 that carries at least onepipette device assembly 10 vertically above a horizontally disposedworkstation deck 304. The pipette device assembly 10 can comprise asingle channel pipetting head or a multi-channel pipetting head.

Additionally, the robotic gantry 302 typically provides two or threedegrees of freedom wherein three degrees of freedom compriseslongitudinal translation along an axis defining an X-axis, latitudinaltranslation along an axis defining a Y-axis, and vertical (up and down)translation along an axis defining a Z-axis so that the pipette deviceassembly 10 can move along the length (X-axis) and width (Y-axis) of thedeck and vertically up and down (Z-axis) relative thereto. With twodegrees of freedom, the robotic gantry is typically provided with theability to translate the pipette device assembly 10 vertically andeither longitudinally or laterally.

In one example embodiment, the automated pipetting workstation 300further comprises a main controller 306, a pipette axis controller 308,and a power supply 310 that provides power for the main controller 306,the pipette axis controller 308, and the pipette device assembly 10.

Additionally, and in one example embodiment, a computer/controller 320can also be employed with the workstation 300 and communicate with themain controller 306 and the pipette axis controller 308 for controllingthe robotic gantry 302 and pipette device assembly 10 including theassociated process protocols of the pipette device assembly 10 such asthe disposable pipette tip 220 attaching and ejection (coupling anddecoupling) processes detailed below.

In one example embodiment, the computer/controller 320 typicallycomprises a processor device or central processing unit (CPU) 322, ahardware read only memory device (ROM) 324, a hardware main memorydevice (RAM) 326, a hardware storage memory 328 comprising anon-transitory computer readable medium or memory 330 having anoperating system 332 and software 334 such as user defined processes 336for the pipette device assembly 10 stored thereby, a user display 338, auser input device 340, an input interface 342, an output interface 344,a communication interface device 346, and a system bus 348 whichcomprises one or more conductor or communication paths that permitcommunication among the devices of the computer/controller 320.Computer/controller 320 may also be operatively couple to LAN and/orserver 350. A power supply 352 provides power for thecomputer/controller 320.

Examples of the above delineated automated pipetting workstation 300including software are presently manufactured and sold by HamiltonCompany, the assignee of the present patent application, located at 4970Energy Way, Reno, Nev. 89502, United States of America.

Pipette Tip Pickup Process with Expanding Mandrel Collet Coupling Device

FIGS. 21 through 31 illustrate details of an example embodiment ofsuccessive stages of a pipette tip pickup process and, in particular, amethod of securing attachment of the pipette tip 220 to the expandingmandrel collet coupling device 100 operatively carried by the pipettedevice 20. As noted above, and in one example embodiment, the pipettetip 220 may be supported by a support surface 282.

As illustrated in FIG. 21, the expanding mandrel collet coupling device100 is connected to the pipette device 20, and upon command, thecoupling device 100 is positioned over the open proximal end 232 of thepipette tip 220 wherein each of their respective central longitudinalaxis is aligned along the Z-axis. The eject sleeve 62 is in the ejectposition, the squeeze sleeve 46 is in the unsqueezed position, theexpanding mandrel collet 170 is in the relaxed state, and the distalO-ring 140 is in the unsqueezed state.

Next, FIG. 22 illustrates the expanding mandrel collet coupling device100 being moved down along the Z-axis into the pipette tip 220 forlowering the distal, elastomeric carrying portion of the coupling device100 to pass into the interior cylindrical proximal end portions of thepipette tip 220 to bring the distal O-ring 140 into contact with theannular sealing seat or stop surface 270 of the tip 220 whilemaintaining the distal O-ring 140 in the unsqueezed state and before theupwardly facing annular shoulder seat or stop surface 260 of the pipettetip 220 and the downwardly facing axial stop disk surface 196 of thestop disk 194 are mated.

Next, FIG. 23 illustrates the coupling device 100 being further moveddown along the Z-axis. Additionally, and referring to FIGS. 23 through25, the squeeze sleeve 46 is moved down along the Z-axis and pushesagainst the LLD circuit ring end 366 which contacts with and pushesagainst the top surface 214 of the annular wedge 210 that surmounts theexpanding mandrel collet 170 while maintaining the plurality of radiallyoutwardly projecting segments 200 in the unexpanded state as detailed inFIG. 24, maintaining the distal O-ring 140 in the uncompressed state asdetailed in FIG. 25, and before the stop surface 260 of the pipette tip220 and the axial stop shoulder surface 196 of the stop disk 194 aremated such that a gap 298 is maintained between the stop surface 260 ofthe pipette tip 220 and the axial stop shoulder surface 196 of the stopdisk 194 of the expanding mandrel collet 170 as detailed in FIG. 23.

Next, FIG. 26 illustrates the squeeze sleeve 46 being moved further downalong the Z-axis for pushing the annular wedge 210 against the interiorsurface 192 of the plurality of radially outwardly projecting segments200 for pushing them radially outwardly out and abutting the exteriorradially outwardly facing rounded surfaces 202 of the plurality ofradially outwardly projecting segments 200 against the upper axiallyarcuate circumferential surface sector portion 250 of the groove 246 ofthe disposable pipette tip 220 as detailed in FIG. 27 for starting theprocess of squeezing or pushing the plurality of radially outwardlyprojecting segments 200 into the groove 246 and initially into abutmentwith the upper axially arcuate circumferential surface sector portion250 of the axially arcuate circumferential interior surface 244 definingthe groove 246. As illustrated in FIG. 26, the action of the pluralityof radially outwardly projecting segments 200 extending or beingprojected into the groove 246 as detailed in FIG. 27 causes an axialupward force that starts the process of pulling the pipette tip 220 upfor starting a process of seating the annular shoulder seat surface 260of the pipette tip 220 with the axial stop shoulder surface 196 of thestop disk 194 for closing the gap 298 (FIG. 23) and compressing thedistal O-ring 140 with the sealing seat or stop surface 270 of the tip220 as detailed in FIG. 28.

FIG. 29 illustrates the squeeze sleeve 46 being moved down along theZ-axis a configured predetermined length until it is locked in positionresulting in the annular wedge 210 being stopped and locked in positionby the squeeze sleeve 46.

As a result, the plurality of radially outwardly projecting segments 200are radially extended to a desired distance or value as exemplified inFIG. 30 for fully seating the axial stop shoulder surface 196 of theexpanding mandrel collet coupling device 100 against the annularshoulder seat surface 260 of the pipette tip 220 with the seating of thetwo surfaces 196, 260 being along an X-axis substantially perpendicularto the Z-axis for forming a normal datum between the two axes.

Concurrently, the distal O-ring 140 is compressed to a desired distanceor value as exemplified in FIG. 31 for seating the distal O-ring 140with the annular sealing seat surface 270 of the tip 220 such that itscross-section is in its final compressed non-circular form therebycompleting the coupling of securing the attachment of the pipette tip220 with the expanding mandrel collet coupling device 100 operativelycarried by the pipette device 20.

Upon completion of the above detailed securing attachment process, theplurality of radially outwardly projecting segments 200 and the distalelastomeric element 140 work in combination to produce a segment andseal coupling that provides a fluid-tight seal wherein the plurality ofradially outwardly projecting segments 200 are at least partiallyreceived within the circumferential groove 246 and at least partiallyseated on the circumferential arcuate interior surface 244 (FIG. 18)defining the circumferential groove 246 and wherein the distalelastomeric element 140 seals against the surface 270 of the pipette tip220 wherein in one embodiment surface 270 provides a radially inwardlyangled and distally or downwardly extending surface.

Accordingly, the plurality of radially outwardly projecting segments 200move radially outward to engage the circumferential groove 246 (FIG. 18)to couple with the tip 220 and move radially inward for releasing thetip 220 as a function of movement of the annular wedge 210. Applying aforce for moving the annular wedge 210 axially downwards results in theplurality of radially outwardly projecting segments 200 being urged to aradially outward position and releasing the force on the annular wedge210 results in a release of energy from the cantilevered arms 180 (FIG.11) supporting the plurality of radially outwardly projecting segments200 such that the segments spring back from the radially outwardposition to the radially inward position.

Disposable Pipette Tip Ejection Process

FIGS. 21 through 31 illustrate, in reverse, details of successive stagesof an example method or process of ejecting the pipette tip 220 from theexpanding mandrel collet coupling device 100 operatively carried by thepipette device 20. This tip ejection process sequence is similar to theattachment or tip pickup securing process sequence except in reverse andFIG. 34 illustrates a distal O-ring axial force component of thecompressed distal O-ring 140 that provides a force to help remove thetip 220 during the ejection process.

In one example embodiment, the ejection process comprises the steps of:(1) positioning the tip where it is to be discarded, such as a wastecontainer; (2) moving the squeeze sleeve 46 upward wherein force isreleased from the annular wedge 210 and, as a result, this force is alsoreleased from the plurality of radially outwardly projecting segments200 so as to allow retraction from the groove 246 in the tip 220, thedistal O-ring 140 starts to release stored elastic potential energy orspring energy as a force against the tip 220, and wherein the springloaded eject sleeve 62 also pushes against the tip 220 to push it offsuch that the tip begins to release from the plurality of radiallyoutwardly projecting segments 200; (3) continuing the movement of thesqueeze sleeve 46 upward wherein the plurality of radially outwardlyprojecting segments 200 continue to retract from the groove 246 in thetip 220 and wherein the distal O-ring 140 and the spring loaded ejectsleeve 62 pushes against the tip 220 to push it off wherein the tip 220continues to release from the plurality of radially outwardly projectingsegments 200; and (4) further continuing the movement of the squeezesleeve 46 to its upmost position wherein the plurality of radiallyoutwardly projecting segments 200 return to their original retractedfree state and are completely free of the groove 246 in the tip 220 andwherein the distal O-ring 140 returns to its original shape and thespring loaded eject sleeve 62 pushes against the tip 220 until the tipis pushed off of the coupler 100 by the spring loaded eject sleeve 62and the spring loaded eject sleeve 62 becomes fully extended.

In light of the foregoing, those skilled in the art will appreciate thatthese tip mounting and ejection processes are applicable to a wide rangeof mechanically and/or automatically driven pipette types and designs.

Coupling and Ejection Forces

FIG. 32 illustrates a diagrammatical vector diagram of a plurality ofradially outwardly projecting segments 200 of the expanding mandrelcollet coupling device 100 initially extending into the groove 246 withradially rounded surface 202 of the plurality of radially outwardlyprojecting segments 200 contacting the upper corner of the tip grooveabove the center of the segment radius resulting in an axial upwardforce pulling the pipette tip 220 upward. As illustrated in FIG. 32, thesegment force (Fsegment_resultant) for each of the plurality of radiallyoutwardly projecting segments 200 is comprised of two components: anaxial force (Fsegment_axial) component and a radial force(Fsegment_radial) component.

As long as the plurality of radially outwardly projecting segments 200are contacting the upper corner of the tip groove above the center ofthe segment radius (dimension Z in FIG. 33) Fsegment_axial increases asthe distance between the center of the segment radius and corner of thegroove increases. Accordingly, at the beginning of the tip pickupprocess, the segment axial force (Fsegment_axial) starts out low asillustrated in FIG. 32 and, in detail in FIG. 33, and increases to itsmaximum at the end of the tip pickup process as illustrated in FIG. 34.

Referring to FIG. 33, the ratio of Z/R equals SIN (w) and SIN (w) isequal to (Fsegment_axial)/(Fsegment_resultant). As a result,(Fsegment_axial) is equal to (Fsegment_resultant) multiplied by theratio of Z/R. From this, the result is that (Fsegment_axial) increasesas Z increases.

Referring to FIG. 34, the segment axial force (Fsegment_axial) seats thestop disc 194 against the seat 260 of the tip 220 and provides the forcerequired to overcome an O-ring axial force (Fdistal_ring_axial) andcompress the distal O-ring 140. The O-ring 140 has an O-ring force(Fdistal_ring_resultant) that results from being compressed and thisO-ring force comprises two components: an axial component(Fdistal_ring_axial) and a radial component (Fdistal_ring_radial).Additionally, the segment radial force (Fsegment_radial) provides theradial force needed to lock the segment into the tip groove 246 (FIG.18) and the distal O-ring radial force component (Fdistal_ring_radial)provides the radial force needed to maintain the seal against the tip.Furthermore, the segment to tip groove geometry that causesFsegment_axial to increase as the segment enters the groove (increasingdimension Z) helps to overcome the O-ring axial force(Fdistal_ring_axial) so that the distal O-ring 140 can be completelycompressed to the desired extent. Moreover, the distal O-ring axialforce component (Fdistal_ring_axial) provides force to help remove thetip 220 during the ejection process.

Alignment/Misalignment

The axial shoulder surface 196 of coupler 100 and the axial shoulderseat 260 of tip 220 are important for correct tip alignment.Accordingly, the coupler 100 and tip 220 are configured so thatplurality of radially outwardly projecting segments 200 push the axialshoulder surface 196 and the axial shoulder seat 260 together topreclude misalignment because if the shoulders are not properly mated,especially if they are tilted, the misalignment error (E) may besignificant.

For example, and as illustrated in FIGS. 35 and 36, the relationshipbetween the misalignment angle (Ø), the tip axial distance (D) andpositional error (E) is: E=D*TAN (Ø). For example, with a misalignmentangle (Ø) of two degrees and a tip axial distance of ninety millimeters,the positional error (E) is 3.14 millimeters. This is considered to bevery high considering typical positional error tolerances are typicallyplus or minus 0.5 millimeters.

FIG. 37 illustrates correct tip alignment with the axial shouldersurface 196 and the axial shoulder seat 260 in flush contact with oneanother to provide proper alignment and to maintain the tip axialdistance D from the tip seat 260 to the distal end 230 constant toestablish a known and controlled distance of the pipette tip end 230along the vertical or axial axis Z and a perpendicular axis X. This isimportant to allow the pipette device to target small holes and smallvolumes of liquid. Additionally, smaller volumes of liquid can betransferred resulting from the known fixed distance of the pipette tipallowing for a controlled touch of the pipette tip/liquid to the workingsurface 290 onto or from which liquid 292 is to be transferred.

Dimensions and Relationships

Accordingly, for proper use and operation, dimensions between thecoupler 100 and tip 220 are related accordingly.

Referring to FIGS. 15, 38, and 39, the tip groove diameter A must belarge enough to allow the segments 200 to pull the tip 220 up andadequately lock the tip 220 in place. Conversely, if it is too big, thesegments 200 may not be able to be pushed in sufficiently to get a goodlock. Additionally, internal diameters B and C must be larger thanexternal diameter K of stop disc 194 and external diameter L of annularbase 172, respectively. However, they must not be too much bigger, asthis may result in a poor fit and/or misalignment.

Referring to FIGS. 38 and 39, the tip seat to groove dimension S must bematched to the stop disk seat surface 196 to segment 200 centerdimension M. This relationship is critical to the coupling between thetip 220 and stop disc 194.

Referring to FIGS. 19, 38, and 39, the dimension of the tip seat surface260 to the O-ring seal land 266 in FIG. 19, dimension F in FIG. 38, mustmatch the stop disk surface 196 to the distally facing perpendicular lipsurface 171, dimension N in FIG. 39. These dimensions control the amountthat the distal O-ring 140 is compressed, and thus how well it seals.The tip surface 260 and stop disc seating/coupling surface 196 must befully mated in order to provide proper alignment and maintain the tipaxial distance D.

Referring to FIGS. 37 through 39, the dimension D between the tip seat260 to the distal end 230 (or axial distance) along with the mating ofthe coupling seats establish a known and controlled distance of thepipette tip end. This is important to allow the pipette device to targetsmall holes and small volumes of liquid. Additionally, smaller volumesof liquid can be transferred resulting from the known fixed distance ofthe pipette tip allowing for a controlled touch of the pipettetip/liquid to the working surface onto or from which liquid is to betransferred.

Referring to FIGS. 15, 38, and 39, the tip internal diameter G must besmaller than diameter L of base 172 in order to create a seat or landfor the distal O-ring 140 to seal against. If diameter G is too large,then the distal O-ring may not seal well. If the diameter is too small,then the distal O-ring 140 may not fully compress and may prevent thestop disc 194 from seating, or may cause harm to the distal O-ring 140.Additionally, the ramp length H along with the diameter G control theseat or land that mates with the O-ring 140. These dimensions arecritical in providing a good O-ring seal. If ramp length H is too long,then the O-ring may not seal well. If H is too short, then the O-ringmay not fully compress and may prevent the stop disc 194 from seating,or may cause harm to the O-ring 140.

Liquid Level Detection (LLD) Circuit Contacts

Referring to FIG. 40, and in one example embodiment, the pipette deviceassembly 10 further comprises a liquid level detection circuit assembly.The liquid level detection circuit assembly comprises a liquid leveldetection or LLD circuit board 360 comprising processing circuitry 362electrically coupled to a LLD circuit contact 364 operatively coupled tothe squeeze sleeve 46 that is made from an electrically non-conductingmaterial so it is insulated from the rest of the assembly and whereinthe contact 364 terminates to a circuit contact ring end 366 recessed inthe bottom area of the squeeze sleeve 46 that is configured forselectively contacting the circuit contact ring end 366 with annularwedge 210 between the non-contact state illustrated in FIG. 22 and thecontact state illustrated in FIG. 29 and therefore in contact with theplurality of conductive segments or elements coupling with the interiorfirst working surface of a conductive tip 220.

As illustrated in FIG. 29, the LLD circuit contact 364 comprises thering end 366 captured between the squeeze sleeve 46 and the annularwedge 210 wherein electrical closure or contact is made between theprocessing circuitry 362 of the LLD circuit board 360 (FIG. 40) and theannular wedge 210 which is made from electrically conductive material.The annular wedge 210 pushes and makes electrical contact with theplurality of radially outwardly projecting segments 200 which are madeusing an electrically conductive nonpliable material.

Accordingly, with the tip attached and the plurality of radiallyoutwardly projecting segments 200 squeezed or pushed and locked into thetip groove 246 of the tip 220, the plurality of radially outwardlyprojecting segments 200 make electrical contact with the tip 220 whichis also made from an electrically conductive material. As a result, andreferring to FIG. 40, this completes the circuit between the processingcircuitry 362 of the LLD circuit board 360 and the tip 220.

Additionally, the stop disk mounting post or distal mounting flange 36is formed from a non-conducting material. Therefore, the body member 102and the plurality of radially outwardly projecting segments 200 areinsulated from the rest of the assembly.

Furthermore, the processing circuitry 362 of the LLD circuit board 360detects a signal change when the tip 220 contacts liquid thereby havingan ability to detect a surface of a liquid being transferred or asurface onto or from which liquid is being transferred. Again, actuationoccurs when the coupling device 100 is attached to the tip 220 and theplurality of radially outwardly projecting segments 200 are radiallypushed circumferentially and locked into the tip groove of the tip 220.

Alternative Example Embodiments

FIG. 41 illustrates the example embodiment of the expanding mandrelcollet coupling device 100 positioned over the example embodiment of thedisposable pipette tip 220 comprising an alternative sealing seatsurface 2270 having an angle of substantially ninety degrees relative tothe central longitudinal Z axis of the pipette tip 220.

FIG. 42 illustrates the example embodiment of the expanding mandrelcollet coupling device 100 positioned in the disposable pipette tipcomprising the alternative sealing seat surface 2270 wherein the tip 220is lifted up to its final seated state and the annular wedge 210 movedinto its final position for defining the final coupling state with thedistal elastomeric element 140 in the final compressed and seatedsealing state against the alternative sealing seat surface 2270.

FIG. 43 details the final compressed state of the distal elastomericelement 140 against the alternative sealing seat surface 2270.

FIG. 44 illustrates the upper interior of the disposable pipette tip 220comprising another alternative sealing seat surface in the form of acircumferential radially concave sealing seat surface 3270. FIG. 45details the circumferential radially concave sealing seat surface 3270illustrated in FIG. 44.

FIG. 46 illustrates the example embodiment of the disposable pipette tip220 illustrating detail of a further alternative sealing seat surface inthe form of a circumferential radially convex sealing seat surface 4270.FIG. 47 details the circumferential radially convex sealing seat surface4270 illustrated in FIG. 46.

FIG. 48 illustrates the example embodiment of the disposable pipette tip220 illustrating a yet further alternative sealing seat surface in theform of a circumferential upward facing tooth edge sealing seat surface5270. FIG. 49 details the circumferential upward facing tooth edgesealing seat surface illustrated in FIG. 48.

FIG. 50 is a fragmentary, longitudinal sectional, side elevational viewof the example embodiment of the expanding mandrel collet couplingdevice 100 positioned over the example embodiment of the disposablepipette tip 220 comprising an alternative V-shaped groove 2246 definedby an V-shaped circumferential interior surface 2244 of the disposablepipette tip 220 opening toward the longitudinal Z axis and having aV-shaped cross section as illustrated.

FIG. 51 illustrates the expanding mandrel collet coupling device 100being positioned in the disposable pipette tip 220 comprising thealternative V-shaped groove 2246 (FIG. 50) wherein the tip 220 is liftedup to its final state with the rounded surfaces 202 of the plurality ofexpanding mandrel collet segments 200 being extended into the V-shapedgroove 2246 and into abutment against the V-shaped circumferentialinterior surface with the distal elastomeric element 140 in the finalcompressed and seated sealing state against the sealing seat surface 270of the tip.

FIG. 52 illustrates the rounded surface 202 of one of the plurality ofexpanding mandrel collet segments 200 being extended into the V-shapedgroove 2246 and abutting against the V-shaped circumferential interiorsurface 2244 defining the V-shaped groove 2246.

FIG. 53 illustrates the example embodiment of the expanding mandrelcollet coupling device positioned over a second example embodiment of adisposable pipette tip 1220 devoid of arcuate circumferential interiorsurface 244 defining the circumferential annular groove 246.

FIG. 54 details the interior of the second example embodiment of thedisposable pipette tip 1220 which is analogous in all portions with theexception that interrupted interior surface section 242 of the firstsubstantially cylindrical interior surface section 242 illustrated inFIG. 18 is devoid of interruption thereby defining uninterruptedinterior surface section 1242 of the disposable pipette tip 1220 whereinthe interior surface section 1242 defines the first working surface.

FIG. 55 illustrates the example embodiment of the expanding mandrelcollet coupling device 100 positioned in the second example embodimentof the disposable pipette tip 1220 with the stop disk shoulder surface196 of the coupling device 100 abutting against an axial stop surface260 of the second example embodiment of the disposable pipette tip 1220and the rounded surfaces 202 of the plurality of expanding mandrelcollet segments 200 being extended against the interior surface 1242 ofthe circumscribing sidewall of the second example embodiment of thedisposable pipette tip 1220 resulting in a deformation 1244 of theinterior surface 1242 and with the distal elastomeric element 140 in thefinal compressed and seated sealing state against the sealing seatsurface 270 of the second example embodiment of the disposable pipettetip 1220.

FIG. 56 details the rounded surface 202 of one of the plurality ofexpanding mandrel collet segments 200 of the expanding mandrel colletcoupling device 100 being extended against and deforming 1244 theinterior surface 1242 of the circumscribing sidewall of the secondexample embodiment of the disposable pipette tip as is illustrated inFIG. 55.

FIGS. 57 through 67 are fragmentary, longitudinal sectional, sideelevational views of the example embodiment of the disposable pipettetip comprising alternative groove shape embodiments relative to thecircumferential annular tip groove for segments 200 illustrated in atleast FIG. 19 and the V-shaped groove segments 200 illustrated in atleast FIG. 50.

In particular, FIGS. 57 through 67 illustrate respective alternativegroove configurations 2251 through 2261 for receipt of segments 200.

Alternative Example Embodiment Collet 2170

FIG. 68 illustrates a second or alternative example embodiment of anexpanding mandrel collet 2170 which is configured as a directalternative to the expanding mandrel collet 170 (FIG. 5) of theexpanding mandrel collet coupling device 100 (FIG. 5). The expandingmandrel collet 2170 is analogous in function to collet 170, butconfigured to improve performance and longevity.

Referring to FIGS. 68 and 69, the expanding mandrel collet 2170comprises a plurality of circumferentially spaced apart upwardlyextending collet arms 2180 that radially outwardly extend and arcuatelytransition upwardly from the lower annular base portion 2172 andterminating to free segmented ends 2200 defining the segmented collardisposed axially above the lower annular base portion 2172. Theplurality of circumferentially spaced apart upwardly extending colletarms 2180 are separated from one another by one of a plurality ofcircumferentially spaced apart upwardly extending kerfs or slots 2182.

Referring to FIGS. 68 and 69, each of the plurality of upwardlyextending collet arms 2180 comprises a respective lower arm portion 2186transitioning into a respective upper arm portion 2190. In oneembodiment, the plurality of circumferentially spaced apart lower armportions 2186 form a circumscribing lower body portion 2181 and theplurality of circumferentially spaced apart upper arm portions 2190 forma frustoconically shaped circumscribing upper body portion 2183 radiallyoutwardly and upwardly transitioning from the lower body portion 2181.

Referring to FIGS. 68 and 69, the distal or lower annular base portion2172 comprises a distally or downwardly facing base surface 2171. Thedistally facing base surface 2171 downwardly transitions into anabbreviated distal or lower end annular stem surface 2174 thatterminates to a distal or lower annular base portion end 2176 of thelower annular base portion 2172. The base surface 2171 and lower endannular stem surface 2174 define an abbreviated distal end annulargroove.

As illustrated in FIG. 69, the lower annular base portion 2172 furthercomprises an inner cylindrical surface 2175 upwardly transitioning intothe interior annular shoulder stop surface 2177.

As further illustrated in FIG. 69, the lower arm portions 2186 comprisethe circumferentially spaced apart lower end portions 2184 that areattached to the lower annular base portion 2172. The lower arm portions2186 further comprise upper end portions defining medial arm portionshaving interior annular recessed segmented surfaces or grooves 2191 andexterior radially outwardly extending annularly segmented stop diskportions 2194. The segmented stop disks 2194 circumscribe and radiallyextend from an exterior of the medial arm portions of the plurality ofcircumferentially spaced apart upwardly extending collet arms 2180defining an annular segmented stop disk. Each of the segmented stopdisks 2194 comprises a proximally or upwardly facing stop disk surface2198 and a distally or downwardly facing stop disk surfaces 2196.Additionally, the plurality of lower arm portions 2186 comprise innercylindrical or interior segmented surfaces 2188 dimensioned with aninner diameter that closely circumscribes the spacer 160 (FIG. 10) whichcircumscribes the elongated central body member 102 (FIG. 10).

Referring to FIGS. 68 and 69, the plurality of circumferentially spacedapart upper arm portions 2190 upwardly and radially outwardly transitionfrom the respective lower arm portions 2186 and terminate into aplurality of free ends 2199 disposed above and radially outwardly fromthe lower arm portions 2186 wherein the plurality of free ends 2199comprise radially outwardly projecting segments defining segmentedcollar 2200 wherein each segment comprises an exterior outwardly facingsurface 2202 which, in one embodiment is outwardly rounded or arcuate inshape. Accordingly, the upper arm portions 2190 upwardly and radiallyoutwardly transition from the segmented stop disks 2194 to a pluralityof radially outwardly projecting segments defining segmented collar2200. Additionally, the plurality of circumferentially spaced apartradially outwardly and upwardly extending upper arm portions 2190including the segments respectively comprise interior surfaces 2192forming an inclined segmented interior surface complemental to theproximally inclined annular side surface 216 (FIG. 13) of the annularwedge 210 (FIG. 13).

Comparing FIGS. 12 and 69, the expanding mandrel collet 2170 widens thebase of each of the ends 2184 of each of the respective arms 2180relative to the expanding mandrel collet 170 and radially extends theends 2184 of arms 2180 outward in order to increase the radius of eachof the arms 2180 relative to the expanding mandrel collet 170. Pushingthe lower ends outward and increasing their diameter allows a largerchord segment or width at the bottom ends 2184 of each of extending arms2180 wherein the increased width of each of extending arms 2180 improvesthe strength of each of extending arms 2180. Additionally, increasingradial extension at the lower ends 2184 of arms 2180 provides increasedstrength. The coupling function is unchanged.

From an engineering perspective, the extending arms 2180 can be modelledas a cantilever beam in bending. Classical strength of materialstechniques can be used to evaluate material stress when the beam issubject to bending, as occurs when the coupler is engaged anddisengaged. In addition, when bending is done repeatedly, or cyclically,the material stress can be analyzed with regard to fatigue strength toprovide adequate product life. Increasing the width at the base of thebeam, as well as increasing associated radii, are geometry modificationsused to lower stress and improve strength.

Device Aspects

In one aspect, the pipette tip coupling device or expanding mandrelcollet coupling device 100 provides improved life span.

In another aspect, the radially outwardly projecting segments 200 of theexpanding mandrel collet 170 provide a more rigid coupling for providinga stiffer joint between the pipette tip 220 and coupler 100.

In another aspect, the radially outwardly projecting segments 200 of theexpanding mandrel collet 170 pulls the tip 220 up and seats itefficiently.

In another aspect, the coupler 100 will not be affected by ejecting atip in free air. O-ring coupling life is adversely affected when the tipis ejected in free air because the O-ring is scuffed and abraded by thegroove in the tip as the tip is pushed off by the spring loaded ejectsleeve. The hardness of the radially outwardly projecting segments 200resists the harmful acts of this scuffing and abrasion.

In another aspect, the material of the expanding mandrel collet 170 caneasily be made from conductive material in order to provide anelectrical circuit to the tip for liquid level detection or other usesas detailed above.

In another aspect, the radially outwardly projecting segments 200 of theexpanding mandrel collet 170 are formed from hard and durable materialssuch as, but not limited to, metallic or hard plastic to provideimproved life and because the discrete elements or segments are muchharder than the plastic tip, they work into the tip groove moreefficiently than soft elastomeric material such as an O-ring.

In another aspect, the radially outwardly projecting segments 200 can beactivated with a low squeeze/axial force because the mechanical designis efficient. A lower squeeze/axial force requirement improves the lifeon the associated parts providing the axial force. As a result of thislower squeeze/axial force requirement, the radially outwardly projectingsegments 200 allows the lower or distal seal 140 to have improved lifespan because the elastomeric material in not compressed as much.

In another aspect, the coupler 100 allows the lower or distal seal 140to be easily accessed if replacement is required. Also, the lower ordistal seal 140 can be made from a greater variety of materials becauseit does not need to be conductive for the LLD circuit.

In another aspect, maintenance costs are lower because of the improvedlife and easier accessibility to the lower or distal seal.

In yet another aspect, tip alignment to the pipette device 20 isimproved because of improved seating.

Method Aspects

In light of the above, and in a further aspect, an example embodiment ofa method is provided for securing attachment of at least one pipette tipto at least one pipette tip coupler in the form of an expanding mandrelcollet coupling device carried by a pipette device, the methodcomprising: (1) providing a pipette tip comprising a sidewall having aninterior circumscribing surface defining a passage opening extendingbetween an open distal end intended for immersion in a medium to bepipetted and an open proximal end opposite in an axial direction to theopen distal end; (2) providing a pipette tip coupler comprising adistally facing axial stop shoulder surface formed by an axially steppedcoupler shoulder of an exterior circumscribing surface of the pipettetip coupler, the distally facing axial stop shoulder surfacecomplementary to a proximally facing axial stop surface formed by anaxially stepped shoulder surface of the interior circumscribing surfaceof the sidewall of the pipette tip; (3) providing a plurality ofdiscrete coupling elements or segments spaced apart and disposedcircumferentially on said upper seating surface of said pipette tipcoupler body; (4) providing a distal elastomeric element carried by thepipette tip coupler at a location inferior to the axially steppedcoupler shoulder; (5) locating a distal end of the pipette tip couplerover the open proximal end of the pipette tip with an axial alignmentbetween a central longitudinal axis of the pipette tip coupler and acentral longitudinal axis of the pipette tip; (6) translating the distalend of the pipette tip coupler through the open proximal end of thepipette tip until the distal elastomeric element contacts acircumferential radially inwardly angled and distally extending interiorworking surface of the interior circumscribing surface of the sidewallof the pipette tip distal from the axially stepped shoulder of theinterior circumscribing surface of the sidewall of the pipette tip; and(7) axially squeezing or pushing the plurality of discrete couplingelements or segments into a radially extended state of abutment with anupper axially arcuate circumferential surface sector portion of anaxially arcuate circumferential interior surface defining a grooveformed into the interior circumscribing surface of the sidewall of thepipette tip at a location superior to the axial stop surface of thepipette tip for providing a proximally directed radial and axialresultant pre-stress force to the pipette tip for energizing the distalelastomeric element into a compressed state configured for providing theaxial and radial sealing abutment of the outer circumferential portionof the distal elastomeric element with the circumferential radiallyinwardly angled and distally extending interior working surface of theinterior circumscribing surface of the sidewall of the pipette tip, andfor abutting the proximally facing axial stop surface of the pipette tipwith the distally facing axial stop surface of said pipette tip couplerbody to define an axial coupling position of the pipette tip on thepipette tip coupler device.

In light of the present disclosure as set forth above, furtherstructural modifications and adaptations may be resorted to withoutdeparting from the scope and fair meaning of the embodiments of thepresent disclosure as set forth above. For example, FIGS. 57 through 67are fragmentary, longitudinal sectional, side elevational viewsdetailing different alternative example embodiments to thecircumferential annular tip groove 246 illustrated in at least in FIG.19 and the V-shaped groove segments 200 illustrated in at least FIG. 50.In particular, FIGS. 57 through 67 illustrate respective alternativegroove configurations 2251 through 2261 for receipt of segments 200.Additionally, the segments of the coupler may comprise radiallyoutwardly faces complementary to the respective different alternativeexample embodiments of the respective groove configurations 2251 through2261. Accordingly, the first working surface is in the form of, but notlimited to, the respective groove configurations or the uninterruptedconfiguration illustrated in FIGS. 53-56 wherein the first substantiallycylindrical interior surface section 242 is devoid of interruptionthereby defining uninterrupted interior surface section 1242 of thedisposable pipette tip 1220. Furthermore, the tip distal O-ring sealingseat 270 may have different geometries in the form of, but not limitedto, flat conical, concave radius, convex radius, step, et cetera.Moreover, the distal O-ring may have alternate shapes than an O-ring andmay be in the form of, but not limited to, configurations complementaryto the tip distal O-ring sealing seat 270.

INDUSTRIAL APPLICABILITY

The above delineation of the systems, assemblies, devices, and methodsincluding uses and operations, demonstrate the industrial applicabilityof embodiment(s) of the present disclosure.

Accordingly, it should be apparent that further numerous structuralmodifications and adaptations may be resorted to without departing fromthe scope and fair meaning of the embodiment(s) of the presentdisclosure as set forth hereinabove and as described hereinbelow by theclaims. Hence, the spirit and scope of the appended claims should not belimited to the above delineated description of the embodiment(s) of thepresent disclosure. And, in the appended claims reference to an elementin the singular is not intended to mean “one and only one” unlessexplicitly so stated, but rather “one or more.” Moreover, it is notnecessary for a device or method to address each and every problemsought to be solved by the present disclosure, for it to be encompassedby the present claims.

Alternate Pipette Device Assembly 3010

FIGS. 70 through 75 illustrate an alternate example embodiment of apipette device assembly 3010 comprising an example embodiment of apipette device 3020, an example embodiment of a nozzle 3102, and anexample embodiment of a leaf spring coupling device 3100 or pipette tipcoupler for use with a disposable pipette tip 220 that is removablycoupled to the pipette device 3020 by way of the nozzle 3102 and theleaf spring coupling device 3100.

Pipette Device 3020

Referring to FIGS. 71 and 72, the pipette device 3020 comprises a body3022 supporting an aspirating and dispensing device 3024 comprising aplunger 3026 operatively coupled to and driven by a motor 3028. Theplunger 3026 resides within a plunger cylinder 3030 extending from adistal or lower end 3032 of the body 3022 of the pipette device 3020.

Pipette device 3020 further comprises an aspirating and dispensingcylinder 3034 that is at least partially disposed within plungercylinder 3030 at a location axially aligned with and distally below theplunger 3026. Plunger cylinder 3030 distally transitions into a distalmounting flange 3036 for attaching nozzle 3102. The leaf spring couplingdevice 3100 couples at one end with the nozzle 3102 and the leaf springcoupling device 3100 removably couples at the other end with thedisposable pipette tip 220.

Referring to FIGS. 70, 71, 72, 77, and 79, nozzle 3102 comprises anaspirating and dispensing cylinder 3034. The aspirating and dispensingcylinder 3034 further comprises an interior circumscribing sidewall 3038that defines an open ended pipette channel 3040 extending therethrough.The open ended pipette channel 3040 longitudinally extends along alongitudinal channel axis 3080 of the pipette device assembly 3010between an open upper end portion 3042 and open lower end portion 3044of the aspirating and dispensing cylinder 3034 for providing opencommunication between plunger 3026 and an exterior area adjacent todistal mounting flange 3036. The distal mounting flange 3036 isoperatively connected to a nozzle 3102 which in turn is connected to theleaf spring coupling device 3100. An open ended central channel 3136extends through the nozzle 3102 and leaf spring coupling device 3100 toprovide open communication between the tip 220 and the aspirating anddispensing cylinder 3034.

Plunger Carriage 3063 and Eject Sleeve 3062

Referring to FIGS. 70 through 74, the aspirating and dispensing device3024 comprises a lead screw 3067, which is driven by a motor 3028. Alead nut 3054 is operatively connected to the lead screw 3067. In oneembodiment, the lead nut 3054 is threaded and screwed onto the leadscrew 3067. A plunger carriage 3063 circumscribes and is operativelyconnected to the lead nut 3054 such that motion of the motor 3028 drivesthe lead nut 3054 which in turn drives the plunger carriage 3063parallel to the longitudinal channel axis 3080.

An eject block 3065 circumscribes lead screw 3067 and is located belowthe plunger carriage 3063. An eject rod 3069 is operatively connected tothe end of the eject block 3065. The eject rod 3069 extends from theeject block 3065 through the distal or lower end 3032 of the body 3022of the pipette device 3020 via a passageway 3021. An eject spring 3074circumscribes the eject rod 3069. The eject spring 3074 is locatedbetween the distal end of the eject rod 3065 and the distal or lower end3032 of the body 3022 of the pipette device 3020 such that the springforce acts in the direction to push the eject block 3065 away from theplunger carriage 3063.

The pipette device further comprises an eject sleeve 3062 whichcircumscribes the plunger cylinder 3030 and nozzle 3102 and contains theaspirating and dispensing cylinder 3034. Eject sleeve 3062 is used toeject the disposable pipette tip 220 from the pipette device 3020wherein the ejection sleeve 3062 is axially movable relative to theaspirating and dispensing cylinder 3034 and plunger cylinder 3030 andcomprises a proximal or upper end 3064, a distal or lower end 3066, andan ejection sleeve arm 3068 attached at a first end to the ejectionsleeve 3062 adjacent to the upper end 3064 and having an opposing secondend removably attached to a distal end 3071 of the eject rod 3069.

The eject sleeve 3062 is in the free state when no pipette tip 220 ismounted, such as after a pipette tip 220 has been ejected. To mount apipette tip 220, the ejection sleeve spring force must be overcome inorder to axially push the ejection sleeve 3062 to a retracted state asillustrated in FIGS. 71 through 73. Furthermore, the spring 3074 isdimensioned to be sufficiently long such that it provides a force toassist in ejecting the pipette tip 220 until the pipette tip 220 iscompletely decoupled from the leaf spring coupling device 3100.

Nozzle 3102 and Leaf Spring Coupling Device 3100

FIGS. 74 through 75 illustrate nozzle 3102 and leaf spring couplingdevice 3100 which are used to mount pipette tip 220 to pipette device3020.

Nozzle 3102

More specifically, the nozzle 3102 comprises a nozzle mounting portion3103 located at a top end of the nozzle 3102, a nozzle stem portion 3107located at a bottom end of the nozzle 3102 relative to the nozzlemounting portion, nozzle body portion 3105 located between the nozzlemounting portion 3103 and the nozzle stem portion 3107, and a nozzleelastomeric element 3135. Nozzle mounting portion 3103 connects nozzle3102 to distal mounting flange 3036 (FIGS. 71 and 79) of pipette device3020.

As further illustrated in FIGS. 75 and 79, the nozzle 3102 furthercomprises nozzle elastomeric element 3135 coaxially carried around thenozzle stem portion 3107 of nozzle 3102. The nozzle stem portion 3107 islocated at the opposite end relative to the longitudinal central axis3090 of nozzle 3102 from the nozzle mounting portion 3103. In an exampleembodiment, the nozzle stem portion 3107 further comprises a nozzlegroove 3109 and the nozzle elastomeric element is carried within thenozzle groove 3109. In an example embodiment, the nozzle elastomericelement 3135 is an O-ring.

Leaf Spring Coupling Device 3100

As illustrated in FIGS. 74 through 77, the leaf spring coupling device3100 comprises a coupling cylinder 3173, a leaf spring cylinder 3175, adistal stem base 3121, and a distal or lower elastomeric element 3140carried at the distal stem base 3121.

As illustrated in FIGS. 76 and 77, the lower end 3171 of the couplingcylinder 3173 is connected to a leaf spring cylinder 3175. The leafspring assembly 3170 is formed in the leaf spring cylinder 3175. Theupper annular stop shoulder end 3177 of the leaf spring cylinder 3175 islocated at the lower end of the leaf spring assembly 3170. The lowerportion 3122 of the leaf spring cylinder 3175 and is connected to thedistal stem base 3121.

As also illustrated in FIGS. 76 and 77 the distal stem base 3121comprises a the distal cylindrical stem portion surface 3124 thattransitions from upper annular stop shoulder end 3122 into a round endplate 3126 having an upper surface 3128 and a lower surface defined bythe distal or lower annular end face 3130. As illustrated, the end plate3126 has a diameter greater than a diameter of the narrowest portion ofthe distal cylindrical stem portion surface 3124 wherein the distal stemportion surface 3124 defines a distal groove portion 3132 of the leafspring coupling device 3100. When a pipette tip 220 is coupled with leafspring coupling device 3100, the upper annular stop shoulder end 3177will abut the proximally facing axial stop surface 260 of pipette tip220 to prevent the leaf spring coupling device 3100 from being insertedtoo far into pipette tip 220.

Distal Elastomeric Element 3140

As further illustrated in FIGS. 76 and 77, the leaf spring couplingdevice 3100 further comprises the distal or lower elastomeric element3140 coaxially carried at the distal stem portion 3124. When a pipettetip 220 is coupled to the leaf spring coupling device 3100, the distalelastomeric element 3140 serves as a seal.

In one embodiment, and referring to FIGS. 77 and 78, the distalelastomeric element 3140 comprises an annular body 3142. Annular body3142 comprises an interior surface 3144 defining a central opening 3146,a top surface 3148, a peripheral exterior surface 3150, and a bottomsurface 3152. Central opening 3146 is dimensioned to closely or tightlycircumscribe the distal stem portion 3124 of the leaf spring couplingdevice 3100 while shaped to reside within groove 3132 and extendradially outwardly circumferentially beyond end plate 3126 asillustrated in FIG. 76. In a relaxed or unsqueezed state, the distalelastomeric element 3140 comprises a circumferentially continuous,generally circular cross section area 3154 as is illustrated in FIG. 79.

Leaf Spring Assembly 3170

Referring to FIGS. 76, 77 and 82, the leaf spring assembly 3170comprises a plurality of circumferentially spaced apart leaf springs3180 formed in the leaf spring cylinder 3175 and arranged parallel tothe longitudinal central axis 3090 and separated by open vertical slots3182. Leaf springs 3180 are flexible. Each pair of adjacent leaf springs3180 are separated by an open vertical slot 3182. The leaf springs 3180are flexible and are used to retain a pipette tip on the leaf springcoupling device 3100.

Each leaf spring 3180 comprises a retention bump 3202 that protrudesfrom the exterior surface 3185 of the leaf spring 3180. In oneembodiment, each of the plurality of retention bumps 3202 has a roundedsurface protruding from the exterior surface 3185. When a pipette tip iscoupled to the leaf spring coupling device 3100, the plurality ofretention bumps 3202 on the leaf spring assembly 3170 expand into thegroove 246 of pipette tip 220 to hold, or retain, the pipette tip 220 onthe leaf spring coupling device 3100.

Each leaf spring 3180 further comprises a stabilizer plateau 3183 thatprotrudes from the exterior surface 3185 of the leaf spring 3180. When apipette tip is coupled to the leaf spring coupling device 3100, theplurality of stabilizer plateaus 3183 on the leaf spring assembly 3170prevent the pipette tip from rocking. The plurality of stabilizerplateaus 3183 prevent the tip from rotating on the leaf spring coupler3100 about the retention bumps 3202 that are positioned within thegroove 246 of pipette tip 220. Such rocking or rotation contributes tomisalignment between the end of the pipette tip 220 and the longitudinalcentral axis 3090. Further, this type of rocking could disengage thepipette tip seal if a side load is applied. To prevent this problem, inone embodiment, the plurality of stabilizer plateaus 3183 are placed oneach leaf spring 3180 above, or closer to the coupling cylinder 3173relative to, the retention bumps 3202. The plurality of stabilizerplateaus 3183 have an interference fit with the pipette tip 220 when theretention bumps 3202 have expanded into the groove 246 of the pipettetip 220. The plurality of stabilizer plateaus 3183 adds another point ofcontact between the pipette tip 220 and the leaf spring coupling device3100 to prevent the tip from rocking.

Pipette Tip Pickup Process with the Leaf Spring Coupling Device 3100

FIGS. 81-85 illustrate details of an example embodiment of successivestages of a pipette tip pickup process and, in particular, a method ofsecuring attachment of the pipette tip 220 to the leaf spring couplingdevice 3100 operatively carried by the pipette device 3020. As notedabove, in an example embodiment, the pipette tip 220 may be supported bya support surface 282.

As illustrated in FIGS. 73, 77, and 81, the leaf spring coupling device3100 is connected to device 3020 via nozzle 3102, and upon command, theleaf spring coupling device 3100 is positioned over the open proximalend 232 of the pipette tip 220 wherein each of their respective centrallongitudinal axis is aligned along the Z-axis. The leaf springs 3180 arein the relaxed state. The eject sleeve spring 3074 has pushed ejectblock 3065 and the eject sleeve 3062 to the lowest position. Plungercarriage 3063 is positioned up to allow eject block 3065 to move upduring the pipette tip pickup process. The distal elastomeric element3140 is in the unsqueezed state.

Next, FIGS. 73, 76, 82, 83, and 84 illustrates the leaf spring couplingdevice 3100 being moved down along the Z-axis (FIG. 81) into the pipettetip 220 for lowering the distal elastomeric carrying portion of the leafspring coupling device 3100 to pass into the interior cylindricalproximal end portions of the pipette tip 220 to bring the distalelastomeric element 3140 into contact with the annular sealing seat 270of the pipette tip 200 while maintaining the distal elastomeric element3140 in the unsqueezed state. The leaf springs 3180 have entered thepipette tip 220 and are in the compressed state. The pipette tip pushesthe eject sleeve 3062 and eject block 3065 up. At this point, there is agap 3298 between the axial stop surface 260 of the pipette tip 220 andthe upper annular stop shoulder end 3177 of the leaf spring couplingdevice 3100 as detailed in FIG. 82. Additionally, and referring to FIGS.81 and 82, it is shown that the retention bumps 3202 are beginning tomove into the groove 246 of the pipette tip 220.

Next, FIGS. 77 and 85 illustrate the leaf spring coupling device 3100being further moved down along the Z-axis into the pipette tip 220 untilthe leaf spring coupling device 3100 seats firmly against the sealingseat 270 of pipette tip 220. The retention bumps 3202 on the leafsprings 3180 have reached and snapped into the groove 246 on the pipettetip 220 to lock the pipette tip into place on the leaf spring couplingdevice 3100. The distal elastomeric element 3140 has compressed againstthe sealing seat 270 in the pipette tip 220. The stabilizer plateaus areengaged with the tip to prevent the pipette tip from rotating on theleaf spring coupling device 3100.

Upon completion of the above detailed securing attachment process, theplurality of leaf springs 3180 and the distal elastomeric element 3140work in combination to produce a segment and seal coupling that providesa fluid-tight seal wherein the plurality of retention bumps 3202 are atleast partially received within the groove 246 of the pipette tip 220and at least partially seated on the circumferential arcuate interiorsurface 244 (FIG. 18) defining the groove 246 of the pipette tip andwherein the distal elastomeric element 3140 seals against the sealingseat 270 that provides a radially inwardly angled and distally ordownwardly extending surface.

Disposable Pipette Tip Ejection Process with the Leaf Spring CouplingDevice 3100

FIGS. 81-85 illustrate, in reverse, details of successive stages of anexample method or process of ejecting the pipette tip 220 from the leafspring coupling device 3100 operatively carried by the pipette device3020. This tip ejection process sequence is similar to the attachment ortip pickup securing process sequence except in reverse.

As illustrated in FIGS. 72, 73, and 81-85, in one example embodiment,the ejection process includes rotating the lead screw 3067 so theplunger carriage 3063 is driven downward into the eject block 3065. Theeject block 3065 pushes the eject sleeve 3062 downward via itsattachment to the eject rod 3069. The eject sleeve 3062 starts pushingthe pipette tip 220 off the leaf spring coupling device 3100. Thepipette tip 220 does not start to move until the force is great enoughthat the leaf springs 3180 (FIG. 77) compress to allow the retentionbumps 3202 to move out of the groove 246 in the pipette tip 220.

Next, the leaf springs 3180 have fully compressed within the pipette tip220. The pipette tip 220 is no longer vertically retained to the leafspring coupling device 3100. At this point in the ejection process, thedistal elastomeric element 3140 has lost contact with the sealing seat270 and thus the seal has been broken. The plunger carriage 3063continues to drive the eject sleeve 3062 down and pushes the pipette tip220 off of the leaf spring coupling device 3100.

Next, the pipette tip 220 continues to be driven off the leaf springcoupling device 3100. The retention bumps 3202 reach the opening of thepipette tip 220 and the leaf springs 3180 start expanding toward therelaxed state.

At the completion of the ejection process, the pipette tip 220 has lostcontact with leaf spring coupling device 3100. The leaf springs 3180 arein the relaxed state. The eject sleeve spring 3074 has pushed the ejectblock 3065, and the eject sleeve 3062 is in the lowest position. Afterthe pipette tip 220 has been ejected, the plunger carriage 3063 ispositioned up to allow the eject block 3065 space to move up during thenext pipette tip pickup process.

Coupling and Ejection Forces for the Leaf Spring Coupling Device 3100

FIG. 86 illustrates a diagrammatical vector diagram of a plurality ofretention bumps 3202 of the leaf spring coupling device 3100 initiallyextending into the groove 246 with retention bumps 3202 on the leafsprings 3180 contacting the upper corner of the tip groove 246 above thecenter of the retention bump radius resulting in an axial upward forcepulling the pipette tip 220 upward. As illustrated in FIG. 86, theretention bump force, or segment force, (Fsegment_resultant) for each ofthe plurality of retention bumps 3202 is comprised of two components: anaxial force (Fsegment_axial) component and a radial force(Fsegment_radial) component.

As long as the plurality of retention bumps 3202 are contacting theupper corner of the tip groove 246 above the center of the retentionbump radius (dimension Z in FIG. 87) Fsegment_axial increases as thedistance between the center of the retention bump radius and corner ofthe groove 246 increases. Accordingly, at the beginning of the pipettetip pickup process, the segment axial force (Fsegment_axial) starts outlow as illustrated in FIG. 86 and, in detail in FIG. 87, and increasesto its maximum at the end of the pipette tip pickup process asillustrated in FIG. 88.

Referring to FIG. 87, the ratio of Z/R equals SIN (w) and SIN (w) isequal to (Fsegment_axial)/(Fsegment_resultant). As a result,(Fsegment_axial) is equal to (Fsegment_resultant) multiplied by theratio of Z/R. From this, the result is that (Fsegment_axial) increasesas Z increases.

Referring to FIG. 88, the segment axial force (Fsegment_axial) seats theupper annular stop shoulder end 3177 against the axial stop surface 260of the pipette tip 220 and provides the force required to overcome anO-ring, or distal elastomeric, axial force (Fdistal_ring_axial) andcompress the distal elastomeric element, or O-ring, 3140. The O-ring3140 has an O-ring force (Fdistal_ring_resultant) that results frombeing compressed and this O-ring force comprises two components: anaxial component (Fdistal_ring_axial) and a radial component(Fdistal_ring_radial). Additionally, the segment radial force(Fsegment_radial) provides the radial force needed to lock the retentionbump 3202 into the tip groove 246 (FIG. 18) and the distal O-ring radialforce component (Fdistal_ring_radial) provides the radial force neededto maintain the seal against the pipette tip 220. Furthermore, theretention bump to tip groove geometry that causes Fsegment_axial toincrease as the retention bump 3202 enters the groove 246 (increasingdimension Z) helps to overcome the O-ring axial force(Fdistal_ring_axial) so that the distal O-ring 3140 can be completelycompressed to the desired extent. Moreover, the distal O-ring axialforce component (Fdistal_ring_axial) provides force to help remove thetip 220 during the ejection process.

Alignment/Misalignment for the Leaf Spring Coupling Device 3100

The upper annular stop shoulder end 3177 of coupler 3100 and the axialstop surface 260 of tip 220 are important for correct tip alignment.Accordingly, the leaf spring coupling device 3100 and pipette tip 220are configured so that plurality of retention bumps 3202 push the upperannular stop shoulder end 3177 and the axial stop surface 260 togetherto preclude misalignment because if the upper annular stop shoulder end3177 and the axial stop surface 260 are not properly mated, especiallyif they are tilted, the misalignment error (E), which is the same asthat illustrated for the embodiment shown in FIG. 36, may besignificant.

Dimensions and Relationships for the Leaf Spring Coupling Device 3100

Accordingly, for proper use and operation, dimensions between the leafspring coupling device 3100 and tip 220 are related.

Referring to FIGS. 38, 79, and 85, the tip groove diameter A must belarge enough to allow the retention bumps 3202 to pull the tip 220 upand adequately lock the tip 220 in place. Conversely, if the tip groovediameter A is too large, the retention bumps 3202 may not be able to bepushed in sufficiently to get a good lock. Additionally, internaldiameters B and C must be larger than external diameter K of upperannular stop shoulder end 3177 and external diameter L, respectively.However, they must not be too much larger, as this may result in a poorfit and/or misalignment.

Referring to FIGS. 38 and 85, the tip seat to groove dimension S must bematched to the upper annular stop shoulder end 3177 to segment 200center dimension M. This relationship is critical to the couplingbetween the tip 220 and upper annular stop shoulder end 3177.

Referring to FIGS. 19, 38, and 85, the dimension of the axial stopsurface 260 to the O-ring seal land 266 in FIG. 19, dimension F in FIG.38, must match the upper annular stop shoulder end 3177 to the distallyfacing perpendicular lip surface 3179, dimension N in FIG. 85. Thesedimensions control the amount that the distal O-ring 3140 is compressed,and thus how well it seals. The axial stop surface 260 and upper annularstop shoulder end 3177 must be fully mated in order to provide properalignment and maintain the tip axial distance D.

Referring to FIGS. 38 and 85, the dimension D between the axial stopsurface 260 to the distal end 230 (or axial distance) establish a knownand controlled distance of the pipette tip end. This is important toallow the pipette device to target small holes and small volumes ofliquid. Additionally, smaller volumes of liquid can be transferredresulting from the known fixed distance of the pipette tip allowing fora controlled touch of the pipette tip/liquid to the working surface ontoor from which liquid is to be transferred.

Referring to FIGS. 38, 79, and 85, the tip internal diameter G must besmaller than diameter L of the leaf spring coupling device in order tocreate a seat or land for the distal O-ring 3140 to seal against. Ifdiameter G is too large, then the distal O-ring may not seal well. Ifthe diameter is too small, then the distal O-ring 3140 may not fullycompress and may prevent upper annular stop shoulder end 3177 fromseating, or may cause harm to the distal O-ring 3140. Additionally, theramp length H along with the diameter G control the seat or land thatmates with the O-ring 3140. These dimensions are critical in providing agood O-ring seal. If ramp length H is too long, then the O-ring may notseal well. If H is too short, then the O-ring may not fully compress andmay prevent the upper annular stop shoulder end 3177 from seating, ormay cause harm to the O-ring 3140.

Liquid Level Detection

Pipette device assembly 3010 further comprises a liquid level detectioncircuit assembly as described for the pipette device assembly 10 (FIG.40). In an example embodiment, the material of the nozzle 3102 and theleaf spring coupling device 3100 can easily be made from conductivematerial to provide an electrical circuit to the pipette tip 220 forliquid level detection or other uses as detailed above with respect topipette device assembly 10.

Alternative Example Embodiments

FIG. 90 illustrates the example embodiment of the leaf spring couplingdevice 3100 positioned in the disposable pipette tip comprising thealternative sealing seat surface 2270 wherein the tip 220 is lifted upto its final seated state with the distal elastomeric element 3140 inthe final compressed and seated sealing state against the alternativesealing seat surface 2270.

FIG. 91 details the final compressed state of the distal elastomericelement 3140 against the alternative sealing seat surface 2270.

What is claimed is:
 1. A pipette tip coupling device for coupling apipette tip to a pipette device, the pipette tip coupling devicecomprising: a nozzle comprising: a nozzle mounting portion located at atop end of the nozzle; a nozzle stem portion located at a bottom end ofthe nozzle; a nozzle body portion located between the nozzle mountingportion and the nozzle stem portion; and a nozzle elastomeric elementcircumscribing the nozzle stem portion; a leaf spring coupling deviceconnected to the bottom end of the nozzle, the leaf spring couplingdevice comprising: a coupling cylinder for receiving the nozzle; a leafspring cylinder comprising: a leaf spring assembly comprising: aplurality of leaf springs, each leaf spring comprising:  an exteriorsurface;  a stabilizer plateau protruding from the exterior surface;  aretention bump with a rounded surface protruding from the exteriorsurface; and  an upper annular stop shoulder end located at a lower endof the leaf spring cylinder; and a lower portion; a distal stem baseconnected to the lower portion of the leaf spring cylinder, the distalstem base comprising: a distal cylindrical stem portion surface; a roundend plate; a distal groove portion; and wherein the distal cylindricalstem portion surface transitions from the upper annular stop shoulderend into the round end plate forming the distal groove portion; a distalelastomeric element disposed around the distal stem base; an open-endedcentral channel forming an open passageway extending longitudinally fromthe top end of the nozzle through the distal stem base of the leafspring coupling device; and wherein the nozzle stem portion is insertedinto the leaf spring coupling device and abuts an interior surface ofthe leaf spring coupling device to form a seal between the nozzle andthe leaf spring coupling device.
 2. The pipette tip coupling device ofclaim 1 wherein the nozzle stem portion of the nozzle further comprisesa nozzle groove, and wherein the nozzle elastomeric element is carriedwithin the nozzle groove.
 3. The pipette tip coupling device of claim 1wherein the nozzle elastomeric element comprises an O-ring and thedistal elastomeric element comprises an O-ring.
 4. The pipette tipcoupling device of claim 1 wherein the nozzle and the leaf springcoupling device each further comprises an electrically conductivematerial.
 5. The pipette tip coupling device of claim 1 wherein theplurality of leaf springs are configured to radially contract relativeto a relaxed state when pressure is applied and to radially expand whenpressure is released.